土壤加硒对柴油胁迫下三叶草光合荧光特性的影响

以三叶草(Trifolium repens)为供试植物,利用室内盆栽试验,研究土壤加硒(Se)对不同柴油(diesel)质量分数梯度(0、15、20、25g/kg)胁迫下三叶草光合荧光特性的影响,以期探索出一种提高植物在高质量分数柴油胁迫下植物生长的方法,支持补充植物修复技术.结果表明:不同柴油质量分数梯度对三叶草的根茎鲜重有显著的抑制(P0.05),三叶草光合荧光特性在柴油的作用下受到明显的抑制,表现为PSII最大光化学效率(Fv/Fm)、PSII实际光化学效率(ФPSⅡ)、光化学淬灭系数(qP)、净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)随着柴油质量分数的增加显著降低(P0.05),胞间二氧化碳质量分数(Ci)和非光化学淬灭系数(qN)随着柴油质量分数升高逐渐升高.而加硒显著缓解了柴油对植物生长和光合作用的胁迫,表现为根茎鲜重最大分别提高了59.4%、28.9%;光合荧光参数Fv/Fm、ФPSⅡ、qP、Pn、Tr和Gs相对于无硒对照组显著增加,Pn增加了18%～49%;Gs增加了24%～32%;Tr增加了6%～31%;Fv/Fm增加了1.4%～3.2%;qP增加了11.4%～21.5%;ФPSⅡ增加了14.4%～21.0%.而Ci相对于不加硒组呈降低趋势,但并不显著,qP降低了0.8%～2.1%.加硒后三叶草的光合参数和叶绿素荧光参数都显著区别于不加硒对照组,表明三叶草的光合作用受抑制的状态在硒的作用下有显著的改善.因此通过向柴油污染土壤添加低质量分数硒,可以有效缓解柴油对植物光合作用的抑制,促进植物生长.研究结果对植物修复柴油污染土壤有一定的支持补充作用.     

硅对盐胁迫下金丝小枣叶绿素荧光参数和气体交换的影响

以2年生嫁接苗为试材,研究了硅对盐胁迫下金丝小枣光合生理的影响。结果表明:金丝小枣在含3.0和5.0 g/kg NaCl土壤中生长135 d,叶绿素(Chl)含量分别降低12.30%和22.08%,加硅比不加硅Chl含量分别提高9.26%和10.62%;光系统 II(PSII)的潜在化学活性(Fv/Fo)和最大光化学效率(Fv/Fm)分别下降19.96%,34.58%和 8. 86%, 14. 10%,加硅比不加硅 Fv/Fo 和 Fv/Fm 分别提高 32. 25%, 30. 71%和11.26%,12.15%;光合速率(Pn)和气孔导度(Gs)分别下降 11.04%,25.32%和 26.13%,16.22%,加硅比不加硅Pn和Gs 分别提高10.94%,20.87%和42.68%,10.85%。说明盐胁迫下给土壤施硅可缓解盐离子对金丝小枣光合作用的抑制与伤害。     

不同供氮水平对苦苣干物质积累、光合特性及叶绿素荧光参数的影响

采用营养液栽培方式,以'细叶苦苣'为实验材料,研究了5个不同供氮水平处理对苦苣干物质积累、光合气体交换参数和叶绿素荧光参数的影响。研究结果表明:5个不同处理的苦苣植株地上和地下部干物质积累量和叶片的叶绿素相对含量(SPAD值)、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(E)、PSII最大光化学效率(Fv/Fm)以及PSII实际光化学效率(ΦPSII)均随着供氮水平的提高呈现出先升高后降低的趋势,而胞间CO2浓度(Ci)表现出先降低后升高的趋势;不同处理中,供氮水平(8和11 mmol/L)通过提高苦苣叶片光合色素含量、CO2传导能力和PSII光化学反应活性,从而提高了Pn,有效促进了干物质积累。而过低(2 mmol/L)和过高(14 mmol/L)供氮水平不同程度地降低了光合色素含量,抑制了光化学反应活性、从而降低了苦苣叶片光合作用和干物质积累。     

油菜素内酯对干旱胁迫下辣椒叶片活性氧代谢的影响

以辣椒品种湘研6号为材料,研究了干旱胁迫下0.05 mg/L的油菜素内酯(BR)对辣椒叶片活性氧代谢的影响.研究表明,干旱胁迫显著抑制了辣椒叶片净光合速率(Pn)、PSII光合电子传递量子效率(ΦPSII)和光化学猝灭系数(qP),虽然干旱胁迫诱导了非光化学猝灭系数(NPQ)以及超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、过氧化氢酶(CAT)和过氧化物酶(POD)的酶活性,但仍导致叶片PSII最大光化学效率(Fv/Fm)的下降和过氧化氢(H2O2)和丙二醛(MDA)含量的大幅上升;油菜素内酯有效地促进了干旱胁迫下辣椒叶片Pn、ΦPSII、qP和NPQ的增强,也显著增强了SOD、APX、CAT和POD的酶活性,从而减轻了干旱胁迫所导致的Fv/Fm的下降和H2O2和MDA含量的增加.结果表明,油菜素内酯可通过增强碳同化和热耗散能力,并诱导抗氧化酶活性的增加,以促进作物的抗旱性.     

外源茉莉酸对盐胁迫下玉米光合特性的影响

玉米(Zea mays L.),为禾本科玉米属一年生单子叶植物,是全球种植范围最广、产量最高的谷类作物,居三大粮食之首.植物激素被认为在调节植物对逆境胁迫的响应中起关键作用,其中茉莉酸(JA)被认为可调节应激反应,影响植物生长和发育.为研究外源JA对盐胁迫下玉米光合特性的影响,本研究以玉米植株为实验材料,采用1/2 Hoagland液体培养基培养玉米植株,待植株生长到五叶期时,以50 mmol/L NaCl胁迫2 d,之后每24 h叶面喷施1 mmol/L JA,连续喷施2 d,探究在盐胁迫下外施JA对玉米植株的根系形态、光合特性及叶绿素荧光特性的影响.在盐胁迫下,施用外源JA时,玉米植株的Pn增加了31.0%,Gs增加了32.2%.ΦPSII和Fv/Fm显著提高.结果表明JA处理促进了盐胁迫条件下玉米植株根系生长发育,提高了光合系统的能力.外源JA可以减少盐胁迫引起的PSII反应中心的损伤,促进光化学电子的转移,保证碳同化反应的正常化.本研究确定了外源JA对玉米盐胁迫的缓解机理,为缓解玉米盐害提供理论和技术依据.     

盐度对盐生杜氏藻叶绿素荧光参数的影响

本文研究了一次性培养过程中,不同盐度（15、30、60、90、120、150）对盐生杜氏藻PSII最大光能转化效率Fv/Fm、PSⅡ的潜在活性Fv/Fo、PSⅡ的实际光能转化效率ΦPSⅡ、相对光合电子传递效率rETR、叶绿素相对含量及细胞密度的影响.实验结果表明：盐度对盐生杜氏藻的光合作用及生长均有显著影响（P〈0.05）;盐生杜氏藻进行光合作用和生长的最适盐度都为90.相关性分析结果表明： 在整个培养周期中,Fv/Fm、叶绿素相对含量均与细胞密度呈显著的正相关关系.     

利用植物籽粒苋修复铊污染土壤研究（英文）

近年来,随着对铊的强毒性及其对人类健康的高风险认识增加,土壤铊污染问题越来越多地被关注.植物修复是去除土壤重金属污染具有低成本和可持续的技术,适用于铊污染土壤的修复.本研究选择籽粒苋作为测试植物,用于研究铊污染土壤的修复.土壤中铊浓度设置为0,1,5,10,15和20 mg·kg~(-1),经过100 d的盆栽试验,结果表明,随着土壤中铊的浓度升高,植物的生物量、高度、PSII最大量子效率(Fv/Fm)和植物含铊总量均有差异,且植物个体组织(根、茎、叶)中铊的浓度增加;生物富集因子(BCF)在所有实验设置中均随着土壤中铊含量增加而上升,且都大于1;转移系数(TF)也有类似的规律.因此,籽粒苋具有良好的修复铊污染土壤的潜力.     

PEG胁迫对玉米幼苗光合特性和叶绿素荧光参数的影响

为探讨PEG胁迫对玉米幼苗光合生理特征影响,采用水培试验对玉米杂交种郑单958幼苗以10%、15%、20%PEG进行胁迫24、48、72 h后,分别测定了叶片净光合速率(Pn)、蒸腾速率(Tr)、叶绿素荧光参数等光合生理指标。结果表明:随着PEG胁迫浓度增加,玉米幼苗叶片的、Pn、Gs与Tr均显著下降,且胁迫浓度增高以及胁迫时间延长,各指标下降幅度增大,同时基础荧光(F0)、非光化学猝灭(NPQ)呈上升趋势,最大荧光(Fm)、可变荧光(Fv)、PSⅡ潜在光化学活性(Fv/Fo)、PSⅡ最大光化学效率(Fv/Fm)和实际化学效率(φPSⅡ)呈下降趋势。但在10%和15%PEG胁迫下,玉米幼苗叶片中Fo、Fm、Fv、Fv/Fo、Fv/Fm、NPQ和φPSⅡ间均无显著差异,但与20%PEG胁迫下各指标间差异均达到显著水平。可见,随着水分胁迫程度增加,玉米幼苗叶片Pn、Tr、Gs受到抑制,其PSⅡ光能转化效率降低,热能散增加,光化学活性受到抑制,致使光合作用显著降低,影响其生长发育。     

采用PEG模拟干旱胁迫及复水玉米光合补偿效应

采用聚乙二醇(PEG)模拟干旱胁迫方法,研究玉米五叶期水分胁迫期间及复水后叶片叶绿素含量、叶绿素荧光动力学参数、光合参数和可溶性糖的补偿效应.研究结果表明,胁迫期间叶片叶绿素含量、PSⅡ原初光的转化效率(Fv/Fm)和PSⅡ的潜在活性(Fv/Fo)、光合速率均降低,而可溶性糖浓度升高,且降低幅度和升高幅度与胁迫程度正相关;复水后,叶片叶绿素含量、Fv/Fo和Fv/Fm、光合速率及可溶性糖浓度均逐渐恢复,出现补偿和超越补偿效应,恢复所需要时间与胁迫程度正相关.胁迫抑制植株生长,导致同化物消耗减少并在叶片内堆积,光合作用降低,表明旱后复水玉米的生长补偿与光合补偿之间具有正反馈机制.     

绿色木霉固态发酵物对黄瓜幼苗促生作用的影响

目的 探讨绿色木霉固态发酵物对黄瓜幼苗促生作用的影响.方法 以绿色木霉固态发酵物为基质培育的黄瓜幼苗作为实验植株(TK),以灭菌自然土培育的黄瓜幼苗作为对照植株(CK),采用盆栽土培的方法,利用叶绿素荧光成像系统及WinRHIZO根系扫描分析系统测定黄瓜幼苗的叶绿素荧光参数和根系指标.结果 与对照植株比较,施加绿色木霉固态发酵物的黄瓜植株光系统Ⅱ的最大量子产量(Fv/Fm)、有效量子产量(Fv′/F′m)、PSⅡ的潜在活性(Fv/Fo)及光合电子传递速率(ETR)等有明显提高;其根系各项指标均显著优于对照植株.结论 绿色木霉固态发酵物对黄瓜幼苗有促生作用.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.