Spin splitting modulated by uniaxial stress in InAs nanowires

We theoretically study the electronic structure, spin splitting, effective mass, and spin orientation of InAs nanowires with cylindrical symmetry in the presence of an external electric field and uniaxial stress. Using an eight-band k center dot p theoretical model, we deduce a formula for the spin splitting in the system, indicating that the spin splitting under uniaxial stress is a nonlinear function of the momentum and the electric field. The spin splitting can be described by a linear Rashba model when the wavevector and the electric field are sufficiently small. Our numeric results show that the uniaxial stress can modulate the spin splitting. With the increase of wavevector, the uniaxial tensile stress first restrains and then amplifies the spin splitting of the lowest electron state compared to the no strain case. The reverse is true under a compression. Moreover, strong spin splitting can be induced by compression when the top of the valence band is close to the bottom of the conductance band, and the spin orientations of the electron stay almost unchanged before the overlap of the two bands.

The main factor influencing the tensile properties of surface nano-crystallized graded materials

The improved mechanical properties of surface nano-crystallized graded materials produced by surface severe plastic deformation ((SPD)-P-2) are generally owing to the effects of the refined structure, work-hardened region and compressive residual stress. However, during the (SPD)-P-2 process, residual stress is produced simultaneously with work-hardened region, the individual contribution of these two factors to the improved mechanical properties remains unclear. Numerical simulations are carried out in order to answer this question. It is found that work hardening predominates in improving the yield strength and the ultimate tensile strength of the surface nano-crystallized graded materials, while the influence of the residual stress mainly emerges at the initial stage of deformation and decreases the apparent elastic modulus of the surface nano-crystallized graded materials, which agrees well with the experimental results. (C) 2010 Elsevier B.V. All rights reserved.

青杨组(Populus section Tacamahaca Spach)不同种对增强UV-B的反应差异

人类向大气中排放的大量氮氧化合物和氟氯烃类化合物(CFC’s)引起臭氧分子的分解，导致到达地球表面的紫外辐射增加，特别是UV-B辐射增强。本项目以青杨组杨树为模式植物，从形态和生理方面研究了来自不同UV-B背景下的康定杨与青杨在增强UV-B下的反应及其反应差异,并探讨了干旱、施肥对它们抗UV-B能力的影响。杨树具有分布广、适应性强、在生态环境治理和解决木材短缺方面均占有重要位置，研究成果可为生态系统的恢复与重建提供理论依据和科学指导。主要研究结果有以下： 1. 在温室中经过增强UV-B处理，杨树的外部形态及生理活动受到了一定程度的影响。增强UV-B导致康定杨、青杨的生物量、叶面积及节间长度降低，叶片增厚，SOD活性升高，膜伤害增加，而对叶片数目、R/S、叶绿素A、叶绿素B及整个叶绿素含量没有影响。两种杨树对UV-B胁迫的响应存在差异：在增强UV-B条件下，青杨的植株高度、生物量、叶面积、脯氨酸含量、长期用水效率受到的影响大于康定杨，相比而言，康定杨在比叶面积、叶片厚度、可溶性糖含量、UV-B吸收物质的含量及SOD和GPX活性方面增加的程度大于青杨。这些区别说明，来自于高海拔的康定杨比来自于低海拔的青杨对增强UV-B 具有更强的耐性。我们认为二者在叶片厚度、比叶面积、UV-B吸收物质含量及SOD、GPX活性差异是导致对增强UV-B耐性不同的原因。 2. 干旱与增强UV-B对杨树的生长和生理特性均产生了影响，而且两种胁迫共同作用时干旱表现减弱或加剧了UV-B对杨树某些形态和生理特性的影响。 据试验结果，干旱显著地降低了杨树的株高、叶片数目、叶面积，增加了叶片厚度，促进ABA的积累，提高了CAT活性。对于干旱，两种杨树之间也表现出了一定的差异性。可溶性蛋白质和脯氨酸在青杨叶片中得到显著积累，而在康定杨中没有变化。此外，CAT、长期用水效率在康定杨中受到的影响更加明显。长期用水效率的不同变化趋势说明两种杨树对水分胁迫采用了不同的用水策略，康定杨采用的是节水用水策略，提高用水效率，而青杨采用的是耗水的用水策略。根据干旱对叶面积、脯氨酸、ABA含量、CAT活性及长期用水效率等方面的影响，我们认为来自高海拔地区的康定杨比来自低海拔的青杨有更大的耐旱性，这是对生长环境长期适应的结果。在高海拔地区，因霜冻常带来土壤水分不可利用，降低了根系对水分的吸收，树木容易受到的生理性干旱。另外，高海拔的地区低的气温使植株对严寒有较强的耐性，减少了水分的需要。 生长于增强UV-B下的康定杨和青杨植株表现为高度降低，叶面积缩小，比叶面积增加；叶片栅栏组织、海绵组织均受到增强UV-B的影响，其厚度的增加导致整个叶片变厚。增强UV-B还显著提高了杨树的APX活性、UV-B吸收物质含量，而对叶片数目、ABA、可溶性蛋白质含量及CAT活性没有产生影响。试验中也观察到了两种杨树对增强UV-B响应的差异：与康定杨相比，在增强UV-B下青杨株高、叶面积降低的程度更大一些，SOD活性显著提高。另外UV-B吸收物质受到的影响不同。根据这些差别，高海拔的康定杨(3500 m)比来自低海拔的青杨(1500 m)增强UV-B有较强的耐性。 与水分充足情况下UV-B对植株的影响相比，干旱对杨树抗增强UV-B产生了一定的影响，表现为加剧或减弱UV-B对植物的影响，但这种影响与形态、生理指标有关。当干旱与增强UV-B共同作用时，杨树植株的株高、叶面积进一步降低、叶片进一步增厚。就脯氨酸的积累的而言，在没有水分胁迫时，增强UV-B促使它显著增加，而在干旱处理下这种效果变得不明显。干旱对增强UV-B的影响还与杨树的种类有一定的关系。在康定杨中，干旱减弱了增强UV-B对栅栏组织与海绵组织的影响，且在植株高度、叶面积上表现出累加效应，而在CAT上交互作用显著；但在青杨中干旱则加剧增强UV-B对栅栏组织与海绵组织的影响，在植株高度、叶面积及比叶面积上表现出显著的交互作用。据碳同素分析，在水分充足的条件下，无论是康定杨，还是青杨，增强UV-B均导致其长期用水效率的提高，然而当两种胁迫共同作用时，长期用水效率则表现出差异，在青杨中，长期用水效率得到进一步增高，而康定杨中干旱的效应被增强UV-B所减轻。 3. 田间试验表明，杨树的生长、生理特征都受到养分和增强UV-B的影响。施肥对杨树的影响表现为：提高了叶面积、生物量及SOD的活性，降低了抗坏血酸含量。对于施肥作用，两种杨树的反应也有区别：在康定杨中施肥显著增加了的叶片长度、宽度及光合色素的含量，降低了净光合速率、气孔导度及胞间CO2浓度；在青杨中，则SOD、GPX、APX活性表现增加。从试验看出，施肥对来自于高海拔地区的康定杨(3500 m)的影响较大，对来自低海拔的青杨(1500 m)影响较小，这与它们对原产地的生境适应有一定关系。在康定杨生长的高海拔地区，低温度和湿度不能为地上凋落物或土壤中的根分解提供理想的条件，造成当地土壤的低养分状况，所以当肥料施用以后，效果显著。 经过增强UV-B处理，杨树叶片中UV-B吸收物质含量、GPX的活性得到提高，而脯氨酸、丙二醛、可溶性蛋白质、叶绿素及类胡萝卜素含量没有受到影响。对于增强UV-B两种杨树受到的影响也有所不同：在青杨中增强UV-B导致叶面积缩小，生物量、净光合速率降低，APX的活性及长期用水效率的提高，而对康定杨的这些指标没有产生显著影响，相反抗氧化酶的活性明显高于青杨。这些差异性是由于两种杨树对原产地不同UV-B背景的长期适应结果。康定杨长期生长在较高UV-B环境中，对UV-B有较强的耐性。而青杨适应于较低的UV-B环境，对增强UV-B较为敏感。 试验中施肥也影响了植株对增强UV-B的反应，不过这种影响与杨树的种类及测定指标有一定的相关性。例如，在缺肥的情况下，青杨的长期用水效率和康定杨的叶绿素含量都受到增强UV-B的显著影响，而施肥以后这种影响变得不显著。在缺肥的条件下，GPX、APX在青杨中的活性、GPX在康定杨中的活性对增加UV-B反应不敏感；而施肥以后则变化显著，同样胞间CO2浓度在康定杨也有类似的变化。 For past decades, Ultraviolet radiation, especially UV-B reaching the Earth’s surface increased because of depletion of ozone layer resulted from emission of NxO and CFC’s from human activities. In this experiment, different species of Populus section Tacamahaca Spach from different UV-B background were selected as a model plant to assess the effects of enhanced UV-B radiation. Morphological and physiological traits induced by enhanced UV-B were observed and the different responses between P. kangdingensis and P. cathayana were discussed, furthermore the influences of drought and fertilizer on responses induced by enhanced UV-B were studied. Since poplars play an important role in lumber supply, and are important component of ecosystems due to their fast growth and wide adaptation, the study could provide a strong theoretical evidence and scientific direction for the afforestation, and rehabilitation of ecosystem. The results are as follows: 1. The experiment conducted in a greenhouse indicated that morphological and physiological traits of two poplars were affected by enhanced UV-B radiation. Enhanced UV-B radiation not only reduced biomass, leave area and internode length, but also increased leaf thickness and SOD activity as well as MDA concentration and electrolyte rate. However, no significant changes in leaf numbers, root shoot ratio, and total chlorophyll and chlorophyll component were observed. There were different responses to enhanced UV-B radiation between two species. Compared with P. kangdingensis, cuttings of P. cathayana, exhibited lower height increment and smaller leaf area. In addition, there were significant differences in free proline, soluble protein, and UV-B absorbing compounds, and the activity of SOD and GPX, long-term WUE between them. Differences in plant height, biomass, leaf area, free proline concentration, and long-termed WUE showed that P. cathayana were more affected by enhanced UV-B radiation than P. kangdingensis. In contrast, more increase of specific leaf mass, leaf thickness, and soluble sugar, and UV-B absorbing compounds, and activity of SOD and GPX were observed in P. kangdingensis. According to these results, we suggested that P. kangdingensis from high elevation, which adapted to higher UV-B environments, had more tolerance to enhanced UV-B than P. cathayana from low elevation, which adapted to lower UV-B environment. We believe it was the difference of leaf thickness, specific leaf mass, and UV-B absorbing compounds as well as the activity of SOD and GPX resulted in lower adaptation of P. cathayana to enhanced UV-B radiation. 2. Growth and physiological traits of two poplars were affected by both drought and enhanced UV-B radiation. Moreover, it was observed that when two stresses applied together drought could exacerbate UV-B effects or decrease sensitivity to UV-B. In the experiment, drought significantly decreased plant height, leaf numbers, leaf area, and increased leaf thickness, and ABA, and CAT activity of two poplars. There were significant interspecific differences to drought stress. Exposed to drought, soluble protein and proline concentration were increased in P. cathayana but not in P. kangdingensis. However, more changes in CAT and long-term WUE were observed in kangdingensis. Different change in long-term WUE suggests that two poplars adapted different water-use strategies. P. kangdingensis employ a conservative water-use strategy, whereas P. cathayana employ a prodigal water-use strategy. Based on the differences in leaf area, accumulation of free proline and ABA, CAT activity as well as long-term WUE, we believed that P. kangdingensis from high elevation had a greater tolerance to drought than P. cathayana from low elevation，which is the result of adaptation to local environment. In high elevation area, trees are prone to suffer from physiological drought because of un-movable water caused by frost. Besides lower temperature enable the plants had greater adaptability to frost as a results the requirement of water is reduced Enhanced UV-B radiation decreased shoots height, leaf area, and increased specific leaf mass and thickness of palisade and sponge layer as well as APX activity and UV-B absorbing compounds in both species. Whereas, leaf numbers, ABA content, soluble protein and CAT activity showed no differences to enhanced UV-B radiation. Interspecific differences were also observed. Compared with P. kangdingensis, P. cathayana showed lower shoot height and smaller leaf area, higher SOD activity. Besides, variation in UV-B absorbing compounds was found. These differences suggested that P. kangdingensis from high elevation (3500 m) was more tolerant to enhanced UV-B radiation than P. cathayana from low elevation (1500 m). Compared with morphological and physiological changes induced by enhanced UV-B radiation under well-watered conditions, drought exacerbated or decreased these changes. However, these effects vary with parameters measured. When two stresses applied together, shoot height and leaf area further decreased while leaf thickness further increased. Under well-watered conditions, enhanced UV-B radiation significantly increased proline content, but such effect was not observed under drought conditions. The effect of drought on enhanced UV-B radiation was related to species. For example, drought reduced the effects of enhanced UV-B radiation on palisade parenchyma and sponge mesophyll in P. kangdingensis, and additive effects in shoot height and leaf area and interactive effect CAT activity were observed. In contrast, for P. cathayana drought significantly exacerbated the effects of enhanced UV-B radiation on palisade parenchyma and sponge mesophyll; there were noticeable interaction in shoot height, leaf area and specific leaf mass. As far as long-term WUE is concerned, it was increased by enhanced UV-B radiation under well-watered conditions in both species. While different effect was observed between two species in combination of two stresses. Long-term water use efficiency was further increased in P. cathayana whereas the effect was less significant in P. kangdingensis. 3. The field experiment showed that growth and physiological traits of poplars were affected by nutrition and enhanced UV-B radiation. Fertilization significantly increased leaf area, biomass and SOD activity, reduced Ascorbic acid concentration. There was interspecific difference in response to fertilization. For P. kangdingensis, fertilization significantly increased leaf width, leaf length and photosynthetic pigments content while net photosynthetic rate and stomatal conductance, intercellular CO2 concentration were significantly decreased. However, for P. cathayana, these parameters were unaffected except the increase of SOD, GPX and APX activity. From above, it could concluded that P. kangdingensis from high elevation was more affected by fertilization than P. cathayana, This difference was due to adaptation to local environment., The low temperature and moisture where P. kangdingensis was collected can not provided optimum to decompose roots and litter fall as a result the nutrition in soil was poor. Exposed to enhanced UV-B radiation, for both species UV-B absorbing compounds and GPX activity were significantly increased while proline, MDA, soluble protein, chlorophyll, carotenoids were not affected. Different responses were also observed between the two species. Enhanced UV-B radiation caused significant decreases in leaf area, biomass, net photosynthetic rate and increase in APX activity and long-term WUE in P. cathayana but not in P. kangdingensis. In addition, activity in antioxidant enzymes was much higher in P. kangdingensis than in P. cathayana. In the experiment fertilization affected responses of cuttings to enhanced UV-B radiation, but it concern species and parameters measured. Long-term WUE in P. cathayana and chlorophyll in P. kangdingensis were significantly increased by enhanced UV-B radiation under non-fertilization treatments while the increase was not found under fertilization treatment. In contrast, under no fertilization treatment enhanced UV-B radiation did not affected GPX and APX activity in P. cathayana and GPX in P. kangdingensis while significant increase appeared after application of fertilization. Similar effect of enhanced UV-B radiation on intercellular CO2 concentration in P. kangdingensis was observed.

在盐胁迫下外源维生素浸种对小麦发芽及幼苗生长的影响

维生素(Vitamin)又称维他命，为“万年青”产品，是维持人体生命健康必需的一类低分子有机化合物质。维生素对人体健康的作用人们研究很多, 维生素可以增强人体对感染的抵抗力，降低出生缺陷及降低癌症和心脏病发病率等，一旦缺乏，肌体代谢就会失去平衡，免疫力下降，各种疾病，病毒就会趁虚而入；而维生素对作物影响的研究却很少。目前为止，尚无对用维生素浸种的方法来研究外源维生素是否对小麦种子萌发及幼苗生长起调节作用的报道，且对其在小麦抗逆性方面影响的研究甚少，对盐的胁迫抗性研究尚未有人报道。小麦（Triticum aestivum L.）属于拒盐的淡土性作物。盐害不利于小麦生长，严重影响小麦的产量和品质。本研究采用4 种不同维生素VB1、VC、VB6、VPP，分别对供试小麦品种川育12（红皮）、川育16（白皮）小麦浸种后，在一般自然条件下和逆境（盐胁迫条件）下，进行试验。探讨在正常情况下与在不同盐浓度条件下，各维生素及盐浓度对小麦发芽及幼苗生长的影响，并且比较两种不同皮色的小麦在相同盐胁迫条件下的差异表现，同时研究维生素处理的特异性，且哪种维生素对盐害缓解作用最佳。研究结果表明：在无盐胁迫（自然）条件下，对用4 种不同维生素VB1、VC、VB6、VPP 浸种小麦川育12、川育16 后的种子萌发及幼苗生长（幼苗的根长、根重、苗高、苗鲜重）的研究结果表明：4 种外源维生素浸种均对小麦发芽有调节作用，都能提高其最终发芽率。但是提高幅度有所差异。用VB6 浸种后的小麦提高幅度最多，VC 次之，VPP 提高幅度最小。同时，4 种外源维生素浸种对小麦种子的出芽速度及芽后长势也有一定的影响。VB6、VC 处理的小麦种子出芽速度最快，萌发后长势最好；VB1 出芽速度相对较慢，VPP 最慢,但都大于对照；VB1 处理长势略高于对照，VPP 处理的小麦长势则低于对照。从整体来看，VB6、VC处理促进效应明显， VB1 次之，而VPP 在某些方面无效甚至产生负效应。此外，相同的维生素处理对不同的品种的种子萌发、生长效果也存在差异，各种维生素作用于川育12 的效应均强于对川育16。进一步对幼苗根系TTC 还原力及幼苗叶片中硝酸还原酶活性进行测定、分析。研究发现：并非所有种类的维生素对幼苗根系TTC 还原力及幼苗叶片中硝酸还原酶活性的提高都有帮助。幼苗根系TTC 还原力在不同维生素处理下存在显著差异，而与小麦品种关系甚微。经VB6、VC 处理后，根系TTC 还原力测定值均显著高于对照，VB1 不明显，VPP 则略低于对照。VB6、VC 处理的幼苗叶片中硝酸还原酶的含量大于对照，VB1 与对照相差无几，而VPP 处理的川育12 幼苗叶片中的硝酸还原酶活性比对照CK 略高，而在川育16 中则略比对照CK 有所下降，呈现出抑制效应。综上结果表明：VB6、VC 具有促进种子发芽，幼苗生长及根系生长的作用，是较好的促生长剂；VPP 具有抑制作用，是较好的抑制剂，可进一步研究、开发利用。在盐胁迫条件下，对用4 种不同维生素VB1、VC、VB6、VPP 浸种川育12、川育16 后的种子萌发及幼苗生长（幼苗的根长、根重、苗高、苗鲜重）的研究结果表明：在不同盐浓度胁迫条件下， 各处理的种子萌发及幼苗生长均受到不同程度的抑制。随着盐浓度的增加, 发芽率、发芽指数和活力指数成下降趋势；幼苗的根长、根重、苗高、苗鲜重不断降低。4 种维生素处理间也表现出较大差异。VB6、VC 在每个处理中均保持对盐害的缓解作用，VB6 较VC 更易于促进发芽及幼苗生长。最终发芽率高，根系多、长、重，苗高高、重。而VB1、VPP 则表现出抑制作用。在高盐浓度150mM 时，4 种维生素浸种后的种子，其最终发芽率均不能达到40％，但VB6、VC 处理最终发芽率、苗重、根重均高于对照，VPP 最终发芽率、苗重、根重均低于对照。进一步对幼苗根系TTC 还原力及幼苗叶片中脯氨酸含量进行测定、分析。研究发现：不同盐浓度，不同维生素处理、不同品种间存在差异。随着盐浓度的增加（75mM，100mM，150mM），幼苗根系TTC 还原力活性成下降趋势，幼苗叶片中脯氨酸的积累量成上升趋势。VB6 处理脯氨酸含量增加最为明显，VC 次之，VPP 与对照接近，其变化幅度最小。经VB6、VC 处理后的幼苗根系还原强度，在不同盐浓度下，测定值均显著高于对照，VB1 不明显，VPP 则低于对照，产生负效应。此外，品种间表现不尽相同，相同的维生素处理，相同的盐浓度对不同的品种的种子萌发、生长效果也存在差异， 4 种维生素对川育16 的作用均强于川育12，但其影响趋势是一致的。说明VB6、VC 具有耐（抗）盐性，可以促进种子发芽和幼苗生长，是较好的耐（抗）盐拌种剂。 Vitamin is one kind of necessary low molecular compound for humans tosustain health and life. Lots of Studies have been done on the effectc of the vitaminsfor people. Vitamin can help people improve the body's natural resistance to disease,Drop the rate of birth defects、cacers and the incidence of the heart diseases. Ifpeople have less of them, the metabolism of the organism may throw off balance,immunity may drop off, and catch disease; Though the effects for Vitamin to thecrops are limited. up to now, there’s no one use soking seeds of wheats with vitaminsas a method, to study on how the effects will happen on the wheat seed germinationand seedling growth, and there are only few reserches on antireversion force forwheats ,none for the antireversion force in Sault stress condition.Wheat（Triticum aestivum L.）is sensitive to the salt, so the salt damage will doharm to wheat’s growth, it will have an unfavorable impact on the output and thequality of wheat.On this reaserch, we Soaking CHY12(red)、CHY16 (white) wheat seeds withVitamin C, B1, PP, B6 (50mg/L) as a pretreatment first. Then under two condition: one is in the normal environment the other is in different Salinity, we begin ourexperiments. Then disscuss on if the vitamin and salinity affect the wheat seedgermination and seedling growth, and what is the different between the two of them,the result shows that:Under the normal condition, after soaking seeds with VB1、VC、VB6、Vpp，we study on the their seed germination and the seeding growth(the root length andweights, The seedling heights and weights), it shows that all of those four kinds ofvitamin can adjust the seed germination, but different in The growth rate. VB6 isbest for increase, VC comes second,VPP is the worst. Meanwhile, those four vitaminalso have effect on the speed of the sprouting of the wheat. VB6、Vc can faster theseed germination most, and the seedlings are all doing well; VB1 do little effects onthe budding, Vpp is the worst, but all treatments are better than CK; but in Vi, VB1some what above the CK, while VPP lower than that. On the whole, the acceleratingeffect of VB6、VC are obvious, VB1 takes second place, but VPP in some aspects arenoneffective even have negative effect. Furthermore, different kind of seeds with thesame vitamin may different in seed germination and seedling growth, four vitaminson CHY16 is better than CHY12.More studies on TTC reductive capacity of roots and the activity of nitratereductase in the leaves, the reasult shows not all the vitamin can help the seedlings toimprove the TTC reductive capacity and the activity of nitrate reductase. TTCreductive capacity in different treatments shows significant differences,but notcorrelate to the variety of the wheat. The TTC reductive capacity of VB6、Vctreatments are all higher than CK, VB1 is nearly the same as CK, VPP is a littlelower than CK. Through the study of acivity of nitrate reductase, it shows that,VB6、VC are higher than CK ,VB1 is nearly the same as CK also, VPP is a little higher inthe CK of CHY12 but lower in CHY16. Through all the results above: VB6、Vc helpthe wheat seed germination, seedling growth and the growth of roots, is theperfectable factor of stimulating the growth; Vpp is a inhibition, that’ll be furtherreserch,and well develop and utilize in the future.Under the different Salinity condition, after soaking seeds with VB1、VC、VB6、Vpp，we study on the their seed germination and the seeding growth(the root lengthand weights, The seedling heights and weights), it shows that: under differentsalinity, the seed germination and the seedling growth of any treatment are inhibited.With the increase of the concentration, the germination rate, Vi、Gi all had fallen; theroot length and weight, the seedling heights and weights steadily sank down. There are also have pronounced difference between all treatments with four differentvitamins.VB6、VC in all treatments are alleviative the salt damage, VB6 is easier tocause to put forth buds than VC, and it’s quantitative value is the highest in theultimate germination rate, in root and seedlings’ hight and weight. Though the VPP、VB1 are seems to inhibite its growth. Under the high concentration150mM Nacl, theultimate germination rate in all treatments are below the 40%, but VB6、VC’squantitative values in any experiments are higher than CK,while VPP lower thanCK.Then we study on the TTC reductive capacity of roots and the content of Polinein leaves, the result shows that between the different salinity, different vitamintreatments, different varieties of the wheat have discrepancy.along with theincreasing concentraion of the salinity（75mM，100mM，150mM），TTC reductivecapacity of roots decreases, the accumulation of the content of Poline in leaves havean upward trend. The increase of VB6’s treatment are obviously, VC comessecond,VPP is nearly come up with CK, changes a little. In TTC reductive capacity of roots’s reserch, VB6、VC are higher than CK at any time,VB1 is not palpable,VPP is lower than CK, makes negative affect on wheat. In addition, varieties of thewheats are remain different, no matter it shows promoting or inhibiting, all fourvitamins have moreobvious effects on CHY16 than CHY12, but the tendency of theeffection are the same. It is say that VB6、VC can help wheat to standwith the saultwell, and promot in growth，they are the better reagent to mix with the seed.

鲜甘薯快速乙醇发酵条件的初步研究

本文对不同菌种（酵母菌和运动发酵单胞菌）快速生产燃料乙醇的条件进行了研究，实现了鲜甘薯快速转化为燃料乙醇。全文分为两部分： 第一部分：酵母菌快速生产燃料乙醇的条件研究。通过单因素试验，酵母菌快速生产燃料乙醇的条件为：发酵方式采用边糖化边发酵（SSF），蒸煮温度为85 ℃，料水比2:1（初始糖浓度 210 g/kg），糖化酶用量0.75 AGU/g 鲜甘薯，接种量10%（v/w）。在最优条件下，经过24 h发酵，乙醇浓度可达97.44 g/kg, 发酵效率为92%，发酵强度为4.06 g/kg/h。由于采用了低温蒸煮和SSF，可以大大节约能耗，从而降低乙醇生产的成本。同时，利用摇瓶优化的条件，进行了10 L，100 L，500 L发酵罐的放大试验，由于发酵罐初期可以人为通氧，使菌体能迅速积累，发酵时间缩短2 h，发酵效率在90%以上。 第二部分：运动发酵单胞菌快速生产燃料乙醇条件研究。通过单因素试验和正交试验获得了发酵的最佳参数：初始pH值6.0-7.0，硫酸铵5.0 g/kg，糖化酶量1.6 AUG/kg淀粉，初始糖浓度200 g/kg，接种量12.5%（v/w）。经过21 h发酵，乙醇浓度为95.15 g/kg，发酵效率可达94%。同时对不灭菌发酵也进行了研究，发酵效率可达92%。为鲜甘薯运动发酵单胞菌燃料乙醇的工业化生产打下基础。 对发酵结束后的残糖进行了研究。通过薄层层析和葡萄氧化酶测定证明：无论是酵母菌还是运动发酵单胞菌发酵结束后的发酵液中都不含葡萄糖。经过HPLC进一步分析残糖说明：发酵液中已没有葡萄糖成分；经糖化酶水解后仍没有葡萄糖出现；但经酸水解后又出现了葡萄糖，说明结束后的残糖是一些低聚糖结构。有关残糖的结构需要进一步研究。可以通过开发高效的低聚糖水解酶来降低发酵液的残糖，提高原料的利用率。 A new technology for rapid production fuel ethanol from fresh sweet potato by different microorganisms (Saccharomyces cerevisiae and Zymomonas mobilis) was gained in this research. The paper involved two parts: Part 1: The study on fuel ethanol rapid production from fresh sweet potato by Saccharomyces cerevisiae. The following parameters of Saccharomyces cerevisiae was investigated by a series of experiments: fermentation models, cooking temperature, initial sugar concentration and glucoamylase dosage. The results showed that SSF (simultaneous saccharification and fermentation) not only reduced the fermentation time (from 30 to 24h) but also enhanced the ethanol concentration (from 73.56 to 95.96 g/kg). With low-temperature-cooking (85 ℃) using SSF, the Saccharomyces cerevisiae was able to produce ethanol 97.44 g/kg which the fermentation yield could reach to 92% and ethanol productivity 4.06 g/kg/h from sweet potato enzymatic hydrolysis. Furthermore, the savings in energy by carrying out the cooking (85 ℃) and saccharification (30 ℃) step at low temperature had been realized. The results were also verified in 10 L, 100 L and 500 L fermentor. The fermentation yield was no less than 90%. The fermentation time of fermenter was shorter than Erlenmeyer flask. This may be that the aeration in the early fermentation period is available, which lead to the rapidly commutations of biomass. Part 2: The technology of ethanol rapid production with simultaneous saccharification and fermentation ( SSF ) by Zymomonas mobilis，using fresh sweet potato as raw material was studied. The effects of various factors on the yield of ethanol were investigated by the single factor and the orthogonal experiments. As a result, the optimal technical conditions were obtained from those experiments：initial pH value 6.0-7.0, nitride 5.0 g/kg，(NH4)2SO4, glucoamylase 1.6 AUG/kg starch, inoculums concentration 12.5% (v/w). The Zymomonas mobilis was able to produce ethanol 95.15 g/kg, with 94% of the theoretical yield, from fresh sweet potato after 24 h fermentation. The fermentation efficiency of non-sterilized was also reach to 92%. We also analyzed the final fermentation residual sugars of Saccharomyces cerevisiae and Zymomonas mobilis. When the residual sugars were analyzed by thin-layer chromatogram and glucose oxidase, there was no glucose. The analysis of reducing sugars by HPLC showed that there was no glucose existed in the fermentation liquor. However, the glucose appeared after being hydrolyzed by acid. It is indicated that the residual sugars in the final fermentation liquor were the configuration of oligosaccharide, which was linked by the special glycosidic bonds. It was feasible for reducing residual sugars to develope the enzyme that can degradation the oligosaccharide.

Theoretical study on spherical proton emission

The proton radioactivity half-lives of spherical proton emitters are investigated within a generalized liquid drop model (GLDM), including the proximity effects between nuclei in a neck and the mass and charge asymmetry. The penetrability is calculated in the WKB approximation and the assault frequency is estimated by the quantum mechanism method considering the structure of the parent nucleus. The spectroscopic factor is taken into account in half-life calculation, which is obtained by employing the relativistic mean field (RMF) theory. The half-lives within the GLDM are compared with the experimental data and other theoretical values. The results show that the GLDM works quite well for spherical proton emitters when the assault frequency is estimated by the quantum mechanical method and the spectroscopic factor is considered.

Enhanced surface plasmon resonance immunoassay for human complement factor 4

Using an enhanced surface plasmon resonance (SPR) immunosensor, we have determined the concentration of human complement factor 4 (C4). Antibody protein was concentrated into a carboxymethyldextran-modified gold surface by electrostatic attraction force and a simultaneous covalent immobilization of antibody based on amine coupling reaction took place. The sandwich method was applied to enhance the response signal and the specificity of antigen binding assay. The antibody immobilized surface had good response to C4 in the range of 0.02-20 mug/ml by this enhanced immunoassay. The regeneration effect by pH 2 glycine-HC1 buffer was also investigated. The same antibody immobilized surface could be used more than 80 cycles of C4 binding and regeneration. In addition, the ability to determinate C4 directly from serum sample without any purification was investigated. The sensitivity, specificity and reproducibility of the enhanced immunoassay are satisfactory. The results clearly demonstrate the advantages of the enhanced SPR technique for C4 immunoassay.

Theoretical calculation of Flory-Huggins and scattering interaction parameters by means of the lattice fluid theory for PVME/PSD blends

By fitting the spinodals of poly(vinyl methyl ether)/deuterated polystyrene (PVME/PSD) systems, the adjustable parameters epsilon (12)* and delta epsilon* in the Sanchez-Balasz lattice fluid (SBLF) theory could be determined for different molecular weights. According to these parameters, Flory-Huggins and scattering interaction parameters were calculated for PVME/PSD with different molecular weights by means of the SELF theory. From our calculation, Flory-Huggins and scattering interaction parameters are both Linearly dependent on the reciprocal of the temperature, and almost linearly on the concentration of PSD. Compared with the scattering interaction parameters, the Flory-Huggins interaction parameters decreased more slowly with an increase in the concentration for all three series of blends.

The kinetics study in liquid-liquid systems with constant interfacial area cell with Laminar flow

A novel constant interfacial cell with laminar flow is proposed as an approach to obtain extraction kinetics data in liquid-liquid systems. Applications and theoretical fundamentals of the apparatus have been elaborated.. The equation which can express the mass transfer of liquid-liquid system run in the constant interfacial cell with laminar flow is deduced. Simulations from the equations indicate that diffusivity is a suitable factor to represent the characteristics of extraction kinetics rather than the extraction rate in the diffusion controlling step. The dependence of the aqueous phase concentration on time is recommended to determine the extraction regime. The diffusivities of the EuCl3-HDEHP extraction system obtained by different methods are compared to certify the hydrodynamic theory of the cell. The diffusivities of the ErCl3-HEH/EHP extraction system are determined, which show that this technique is a convenient method to obtain the diffusivities in the liquid-liquid system and to determine the extraction regime. (C) 1998 Elsevier Science Ltd. All rights reserved.

MECHANICAL-PROPERTIES OF PHENOLPHTHALEIN POLYETHER KETONE - YIELD STRESS, YOUNGS MODULUS, AND FRACTURE-TOUGHNESS

A series of tensile and three-point bending studies was conducted at various temperatures and loading rates using phenolphthalein polyether ketone (PEK-C). Yield stress, Young's modulus, fracture toughness, and crack opening displacement data were obtained for various conditions. In general, both yield stress and Young's modulus increase with decreasing temperature. However, the relationships between fracture toughness, loading rate, and temperature are very complex. This behavior is due to the simultaneous intersection of viscoelasticity and localized plastic deformation. The increased yield stress is the main factor contributing to the reduction in fracture toughness and crack opening displacement. The relationship between fracture toughness and yield stress are discussed. (C) 1995 John Wiley and Sons, Inc.

APPLICATION OF FACTOR-ANALYSIS TO CORRECTION OF SPECTRAL OVERLAP INTERFERENCE IN INDUCTIVELY COUPLED PLASMA ATOMIC EMISSION-SPECTROMETRY

Correction of spectral overlap interference in inductively coupled plasma atomic emission spectrometry by factor analysis is attempted. For the spectral overlap of two known lines, a data matrix can be composed from one or two pure spectra and a spectrum of the mixture. The data matrix is decomposed into a spectra matrix and a concentration matrix by target transformation factor analysis. The component concentration of interest in a binary mixture is obtained from the concentration matrix and interference from the other component is eliminated. This method is applied to correcting spectral interference of yttrium on the determination of copper and aluminium: satisfactory results are obtained. This method may also be applied to correcting spectral overlap interference for more than two lines. Like other methods of correcting spectral interferences, factor analysis can only be used for additive spectral overlap. Results obtained from measurements on copper/yttrium mixtures with different white noise added show that random errors in measurement data do not significantly affect the results of the correction method.

The involvement of HSP22 from bay scallop Argopecten irradians in response to heavy metal stress

Heat shock protein 22 (HSP22) is an important member of small heat shock protein (sHSP) subfamily which plays a key role in the process of protecting cells, facilitating the folding of nascent peptides, and responding to stress. In the present study, the cDNA of HSP22 was cloned from Argopecten irradians (designated as AiHSP22) by rapid amplification cDNA end (RACE) based on the expressed sequence tags (ESTs). The full-length cDNA of AiHSP22 was of 1,112 bp, with an open reading frame of 588 bp encoding a polypeptide of 195 amino acids. The deduced amino acid sequence of AiHSP22 showed high similarity to previously identified HSP22s. The expression patterns of AiHSP22 mRNA in different tissues and in haemocytes of scallops exposed to Cd2+, Pb2+ or Cu2+ were investigated by real-time quantitative RT-PCR. The mRNA of AiHSP22 was constitutively expressed in all examined tissues, including haemocyte, muscle, kidney, gonad, gill and heart. The expression level in heart and muscle was higher than that in other tissues. The mRNA level of AiHSP22 in haemocytes was up-regulated after a 10 days exposure of scallops to Cu2+, Pb2+ and Cd2+. However, the expression of AiHSP22 did not increase linearly along with the rise of heavy metal concentration. Different concentrations of the same metal resulted in different effects on AiHSP22 expression. The sensitive response of AiHSP22 to Cu2+, Pb2+ and Cd2+ stress indicated that it could be developed as an indicator of exposure to heavy metals for the pollution monitoring programs in aquatic environment.

Examination of Antioxidative System's Responses in the Different Phases of Drought Stress and During Recovery in Desert Plant Reaumuria soongorica (Pall.) Maxim

The aim of this study was to test the protective roles of superoxide dismutases (SODs), guaiacol peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) against oxidative damage and their activities in different phases of the dry down process in Reaumuria soongorica (Pall.) Maxim. leaves. Drought stress was imposed during 100 consecutive days and rewatering after 16, 72, and 100 days. The concentration of hydrogen peroxide (H2O2), malondialdehyde, and SODs activities were elevated significantly with progressing drought stress. POD and CAT activities increased markedly in the early phase of drought and decreased significantly with further drought stress continuation, and POD activity was unable to recover after rewatering. Ascorbate, reduced glutathione, APX, and GR activities declined in the initial stages of drought process, elevated significantly with further increasing water deficit progression and recovered after rewatering. These results indicate that: (1) iron SODs-removing superoxide anion is very effective during the whole drought stress; (2) CAT scavenges H2O2 in the early phase of drought and enzymes of ascorbate-glutathione cycle scavenge H2O2 in further increasing drought stress; and (3) POD does not contribute to protect against oxidative damage caused by H2O2 under drought stress.

Molecular cloning and expression profile of putative antilipopolysaccharide factor in Chinese shrimp (Fenneropenaeus chinensis)

A new antimicrobial protein gene of the anti-lipopolysaccharide factor family (tentatively named as ALFFc) has been cloned from hemocytes of the Chinese shrimp Fenneropenaeus chinensis by rapid amplification of 3' and 5' complementary DNA ends with polymerase chain reaction. The full-length complementary DNA of ALFFc consists of 600 bp with a 369-bp open reading frame, encoding 123 amino acids. The deduced peptide contains a putative signal peptide of 25 amino acids and mature peptide of 98 amino acids. The molecular mass of the deduced mature peptide is 13799.16 Da. It is highly cationic, with a theoretical pI of 10.3. The deduced amino acid sequence of ALFFc showed 56% homology with sequences of Tachypleus tridentatus and L. polyhemus. The tissue expression profile of this gene was studied by Northern blot, and ALFFc transcripts were mainly detected in hemocytes, gill, and intestine. RNA in situ hybridization showed that ALFFc was constitutively expressed in hemocytes. Capillary electrophoresis reverse transcriptase PCR was used to quantify the variation of messenger RNA transcription level during the artificial infection process with Vibrio anguillarum. Significant enhancement of ALFFc transcription appeared during the first 24 hours in response to Vibrio infection. These results provide useful information for understanding the function of ALFFc in shrimp.

Molecular cloning and characterization of a putative lipopolysaccharide-induced TNF-alpha factor (LITAF) gene homologue from Zhikong scallop Chlamys farreri

LPS-induced TNF-alpha factor (LITAF) is a novel transcriptional factor that was first discovered in LPS-stimulated human macrophage cell line THP-1. LITAF can bind to TNF-a promoter to regulate its expression. The first scallop LITAF (named as CfLITAF) was cloned from Zhikong scallop Chlamys farreri by Expressed Sequence Tag (EST) and Polymerase Chain Reaction (PCR) techniques. The cDNA of CfLITAF was of 1240 bp and consisted of a 5' untranslated region (UTR) of 112 bp, a 3' UTR of 678 bp and an open reading frame (ORF) of 450 bp encoding a polypeptide of 149 amino acids with an estimated molecular mass of 16.08 kDa and theoretical isoelectric point of 6.77. A typical conserved LITAF-domain was identified in CfLITAF by SMART analysis. Homology analysis of the deduced amino acid sequence of CfLITAF with other known sequences by using the BLAST program revealed that CfLITAF was homologous to the LITAF from human and rat (Identity = 46%), cattle, horse, mouse and chicken (Identity = 48%), western clawed frog (Identity = 42%), and zebrafish (Identity = 50%). The mRNA expression of CfLITAF in different tissues including haemocytes, muscle, mantle, heart, gill and gonad, and the temporal expression in haemocytes challenged by LPS or peptidoglycan (PGN) were measured by Real-time RT-PCR. CfLITAF mRNA transcripts could be detected in all tissues examined and be up-regulated in haemocytes after LPS challenge. No significant changes were observed after PGN stimulation. All these data indicated the existence of LITAF in scallop and also provided clue on the presence of TNF-alpha-like molecules in invertebrates. (C) 2007 Elsevier Ltd. All rights reserved.