水稻需水量对旱涝交替胁迫的响应效应

通过农田水位调控以降低旱涝胁迫对水稻生长影响的研究已成为稻作节水学科研究领域的热点问题.本文基于水位调控技术研究了旱涝交替胁迫下水稻生理胁迫程度和需水量的变化.结果表明:拔节孕穗期、抽穗开花期水稻抗旱涝胁迫能力较强,分蘖期和乳熟期较弱;水稻在两个生育期内受到旱涝交替胁迫时,水稻前期胁迫将对后期生长有影响且因后者对应水位不同而存在差异,其中拔节孕穗期和抽穗开花期连续进行旱涝交替胁迫处理使水稻生理生长机能遭到破坏,对旱涝胁迫的抵抗能力下降;旱涝交替胁迫下水稻全生育期需水量变化按照拔节孕穗期抽穗开花期乳熟期分蘖期依次降低,此外,除乳熟期处理对旱涝胁迫调控表现为不显著,其余生育期旱涝胁迫对需水量变化影响均显著.     

水稻不同生育阶段稻田水位调控对产量因子及产量的影响

以稻田水位作为调控指标,对水稻分蘖期、拔节孕穗期、抽穗开花期和乳熟期进行受旱试验,根据试验资料分析水稻不同生育期受旱对产量及其构成因子的影响。研究表明：水稻分蘖期受旱,对有效穗数最为不利,反而复水后会使穗粒数、结实率有所增加,对千粒质量影响不大,如分蘖期严重受旱,将导致严重减产;拔节孕穗期对水分很敏感,受旱对穗粒数和结实率均产生不利影响,会严重降低产量,而对千粒质量影响并不显著;抽穗开花期受旱对穗粒数、结实率和千粒质量均产生不利影响;乳熟期受旱主要对千粒质量产生不利影响。通过灰色关联度分析,得出水稻产量构成因子对产量贡献最大的为有效穗数。     

水稻孕穗期土壤干燥引起的不育

水稻孕穗期干旱对籽粒产量影响最大，因为干旱对籽粒产量影响最大，因为干旱使不育性急剧增加。我们的目的是确定干旱期间所引起的不育性的生理过程。试验品种３个：一个水稻品种、２个旱稻品种。采用盆栽，设置几种土壤处理，在孕穗期处理１０天，随着土壤干旱程度的增加，３个样品剑叶伸长率（ＬＥＲ）、干物质生产量（ＤＭＰ）和叶片水势（ＬＷＰ）都降低，而不育度增加。３个品种不育性的增加与ＤＭＰ的降低密切相关。过去认为是     

POD活性与水稻抗旱性的关系

以５种抗旱性不同的水、旱稻品种在水分胁迫条件下全生长期的叶为实验材料，采用愈创木酚法ＰＯＤ活性，探讨不同水稻品种生长期对水分胁迫的反应及其与抗旱性的关系。结果表明，受到水分胁迫的水、旱稻ＰＯＤ活性的高于对照；孕穗期和抽穗期是水分敏感期，在此期间，ＰＯＤ活性上升的幅度高于其它生长期。拔节期和成熟期是水旱稻全生长期中的ＰＯＤ活性较低的时期。     

水稻品种以及施肥措施对稻田甲烷排放的影响

１９９４年４月至１０月，在北京稻田试验田研究了不同水稻品种对甲烷排放的影响以及施肥措施对降低甲烷排放和提高水稻产量的匹配关系。实验表明稻田甲烷排放在品种之间存在着明显差异，实验中品种间甲烷排放通量最大差异可达到五倍。以有机肥混合硫酸铵作底肥并配合不同时间和不同用量的硫酸铵作追肥与仅施混合底肥不施施硫酸铵作追肥的相比较可减少甲烷排放约５８％，水稻产量提高３１．７％。可明显地抑制水稻生长期的甲烷排放高     

氮肥处理对水稻群体小气候及其产量的影响

为研究不同氮肥处理对水稻群体生态的影响,以杂交水稻F优498为材料研究不同氮肥施用水平下群体小气候、产量及纹枯病发病情况的差异.结果表明,随着氮肥施用量的增加杂交水稻的产量增加,但在高氮条件下产量增加不显著;增施氮肥后虽然结实率和千粒重下降,但是有效穗数显著增加(30%左右)导致了单株产量(19%左右)的提高.同时氮肥增加后其群体通透性(包括透光性和透气性)显著降低,温度降低但湿度增加;这一系列群体小气候的恶化导致纹枯病发病程度增加.氮肥过低无法保证产量,过高则会引起群体生态环境恶化.在中等施氮水平下(150 kg/hm~2),水稻的产量既不会显著降低,群体小气候条件也优于高氮处理.进一步研究不同肥料处理对群体小气候和产量的影响,可以探索出既能达到高产又可以降低病虫害发生的最优措施.     

水稻倒伏的原因及控制措施

水稻倒伏不仅影响水稻产量，同时还影响稻米的品质，生产中水稻倒伏以后一般减产15-20％，灌浆前倒伏可减产30％以上。     

POD活性与水稻抗旱性的关系

以５种抗旱性不同的水、旱稻品种在水分胁迫条件下全生长期的叶为实验材料，采用愈创木酚法测定ＰＯＤ活性，探讨不同水稻品种生长期对水分胁迫的反应及其与抗旱性的关系．结果表明，受到水分胁迫的水、旱稻ＰＯＤ活性均高于对照；孕穗期和抽穗期是水分敏感期，在此期间，ＰＯＤ活性上升的幅度高于其它生长期；拔节期和成熟期是水早稻全生长期中ＰＯＤ活性较低的时期．可以认为，在水分胁迫时，ＰＯＤ活性变化与在大田种植的水、旱稻抗旱性有一定的相关性．通过测定水分胁迫条件下敏感期ＰＯＤ活性变化幅度，可作为某一品种抗旱能力的生物化学指标．     

不同基因型水稻对低温潜沼性逆境的耐受能力及其农艺表现

低温潜沼性逆境是我国稻区常见逆境之一,研究不同基因型水稻对低温潜沼性逆境的耐受能力及农艺表现,对于提高稻田产量具有重要的理论意义和实践意义.研究选取四川盆地常用水稻品种,采用田间试验的方法,观测并分析不同水稻品种的分蘖动态、穗部性状等农艺指标.结果表明:① 低温潜沼性逆境下,耐受能力较强的协优027和冈优188,在分蘖期（5月306月30日）具有较强的分蘖能力,其最大分蘖数分别为24.93和23.90,显著高于其它参试品种;其平均株高增长率在分蘖期分别为5.2%和5.7%,显著低于其它参试水稻品种.② 协优027和冈优188在低温潜沼性逆境下的结实率较非逆境下的结实率分别降低5%和2%,穗长分别降低0.8%和0.1%,降低程度显著低于其它参试品种.③ 协优027和冈优188在低温潜沼性逆境下的稻谷产量分别为7.16,6.61 t/hm 2,显著高于辐优151（4.81 t/hm2）和川谷优204（3.43 t/hm2）.④ 低温潜沼性逆境下,水稻耐潜指数与水稻产量间的相关系数为0.64（P0.05）,与水稻产量降低程度间的相关系数为-0.78（P0.01）.低温潜沼性逆境耐受能力较强的水稻品种（协优027和冈优188）,在低温潜沼性逆境下的分蘖数较多,结实率和穗长降低程度较低,产量降低程度较小,更容易获得高产.水稻耐潜指数可以用来评价不同基因型水稻对低温潜沼性逆境的耐受能力,耐潜指数越高,其在低温潜沼性逆境下产量降低程度越小.     

冀东滨海稻区稻曲病侵染规律研究Ⅱ侵染时期

稻曲病是当前造成稻谷产量损失和降低稻米经济价值最主要的病害之一。国内外对稻曲病侵染规律研究有较多的报道。在侵染时期方面,大都认为在水稻孕穗期:I. Kegarmi(1960)在孕穗期采用向叶鞘内注射厚垣孢子悬浮液的方法接种成功;R. A. Singh(1985)认为菌核在六七月份的雨季萌发,子囊孢子成熟后与早播水稻扬花期一致,子囊孢子落到花器上侵染。广东黎毓千(1986)报道孕穗后期为此病的侵染时期。江苏黄正兴(1984)认为病菌的侵染时期在水稻破口至齐穗阶段。本研究自1987—1989年连续三年人工接种,对冀东滨海稻区稻曲的侵染时期进行试验,现将研究结果简报如下:     

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.     

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.     

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).     

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.