首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
使用LI-6400便携式光合测定系统,研究了湿地松优良半同胞家系的光和CO2响应情况,结果表明:不同湿地松半同胞家系光响应曲线、CO2响应曲线的特征参数在家系品种间有极显著差异。湿地松各半同胞家系1龄针叶在全年中以3至4月份、2龄针叶以4月份的表观光量子效率为最高,所有针叶以5月份最低, 各家系1龄、2龄针叶的羧化效率以5月最低,8至9月最高。所有家系的1龄针叶、2龄针叶的表观光量子效率、羧化效率均高于普通品种,1龄针叶的表观光量子效率、羧化效率要高于2龄针叶的。具有较高的表观光量子效率、羧化效率、光饱和点、CO2饱和点和较低的光和CO2补偿点,是湿地松优良半同胞家系具有较高生长量和产量的主要生理原因。  相似文献   

2.
使用LI-6400便携武光合测定系统,研究了湿地松优良半同胞家系的光和CO2响应情况,结果表明:不同湿地松半同胞家系光响应曲线、CO2响应曲线的特征参数在家系品种间有极显著差异.湿地松各半同胞家系1龄针叶在全年中以3至4月份、2龄针叶以4月份的表观光量子效率为最高,所有针叶以5月份最低,各家系1龄、2龄针叶的羧化效率以5月最低,8至9月最高.所有家系的1龄针叶、2龄针叶的表观光量子效率、羧化效率均高于普通品种,1龄针叶的表观光量子效率、羧化效率要高于2龄针叶的.具有较高的表观光量子效率、羧化效率、光饱和点、CO2饱和点和较低的光和CO2补偿点,是湿地松优良半同胞家系具有较高生长量和产量的主要生理原因.  相似文献   

3.
干旱条件下蚕豆光合和生理特性变化研究   总被引:3,自引:2,他引:1  
通过盆栽控制水分试验方法,对土壤适宜含水量(90%fθ)、轻度干旱(70%θf)、中度干旱(50%θf)和重度干旱(30%fθ)4种水分条件下蚕豆叶片光合和生理特性进行了系统研究.结果表明:随着干旱程度加重,蚕豆叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)受到了明显抑制,细胞间隙CO2浓度(Ci)则先升高后下降再上升;随着胁迫时间的延长,蚕豆叶片细胞膜透性、丙二醛(MDA)含量和渗透调节物质含量明显增加,叶片内的相对含水量和叶绿素含量减少,保护酶系统(SOD,POD,CAT)活性随着胁迫时间的延长,总体表现为先升高后降低.  相似文献   

4.
红皮柳(Salix purpurea)是我国西北地区重要的乡土树种,生长快、适应性强,在水土保持、防护林和生物质能源等方面发挥重要作用。以红皮柳扦插苗为研究材料,通过盆栽试验,在4种不同程度干旱胁迫处理(对照、轻度干旱、中度干旱和重度干旱胁迫)下,测定叶片的光合作用参数及生长量,分析探讨干旱胁迫对红皮柳光合特性及生长的影响。结果表明:在轻度、中度和重度干旱胁迫下,红皮柳叶片净光合速率(Pn)日均值分别比对照下降10.4%(P0.05)、17.9%(P0.05)和58.2%(P0.05),中度和重度干旱胁迫下Pn下降量达到显著水平;随着干旱胁迫程度的加剧,Pn的下降伴随着蒸腾速率(Tr)和气孔导度(Gs)的显著下降,水分利用效率(EWUE)逐渐升高,胞间CO_2浓度(Ci)先下降后上升;轻度干旱胁迫和中度干旱胁迫下Pn的降低是由于气孔限制引起,而重度干旱胁迫下受到气孔因素与非气孔因素的共同作用。而且,红皮柳生长受到干旱胁迫的显著影响,随着干旱胁迫程度的加重,株高和基径的相对增长率下降程度增大。  相似文献   

5.
水分胁迫下玉米幼苗光合变化和生理特性分析   总被引:2,自引:0,他引:2  
对不同水分胁迫下玉米幼苗光合变化和生理特性的系统研究表明,在轻度干旱初期,玉米叶片光合速率(Pn)、蒸腾速率(Tr)有所下降,同正常供水(CK)条件相比差异不显著;在中度和重度干旱条件下,Pn,Tr开始就比CK明显降低并不断增大,其间气孔导度(Gs)则同光合速率、蒸腾速率几乎呈平行关系,同时幼苗生长也受到了明显抑制;3种胁迫下,叶片含水量也逐渐减少,丙二醛(MDA)含量、细胞膜透性和渗透调节物质含量随着胁迫程度加深和胁迫时间延长明显增加,保护酶系统(SOD,POD,CAT)活性随着胁迫时间的延长,总体呈现出先升高后降低的趋势.  相似文献   

6.
4个杜梨半同胞家系苗期耐盐性分析   总被引:1,自引:0,他引:1  
【目的】研究4个杜梨半同胞家系耐盐性差异,为沿海地区杜梨耐盐品种的筛选和推广提供参考。【方法】以滨海地区采集的4个杜梨半同胞家系实生苗为试材[编号为盐城(YC)、青岛20(QD20)、青岛14(QD14)和连云港(LYG)],采用室内盆栽方法,以不同浓度NaCl(质量分数梯度为0、0.2%、0.4%、0.6%、0.8%)进行盐胁迫处理,通过对其存活率、苗高、地径、生物量及根冠比、细胞膜透性、叶绿素含量和光合特性等生长和生理指标测定,分析4个杜梨半同胞家系耐受盐胁迫的能力,并运用因子分析和隶属函数法对4个家系的耐盐性进行综合评价。【结果】随着盐胁迫浓度升高,4个杜梨家系幼苗成活率均逐渐降低,其中YC成活率最高;根冠比呈先上升后下降的趋势,YC和QD14在0.6%盐处理下达到最大值,而QD20和LYG分别在0.2%和0.4%下达最大值;各家系的苗高、地径和总生物量均受到显著抑制,在0.2%盐处理处理下,YC降幅最小,同比对照分别降低了37.00%、18.69%和24.98%,而LYG的苗高增量和总生物量降幅最大,分别降低了95.42%和50.71%;4个杜梨家系叶片的净光合速率、气孔导度、蒸腾速率和叶绿素含量变化趋势一致,均随着胁迫浓度升高而降低,其中YC降幅最小,而LYG降幅最大;叶片细胞膜透性却逐渐升高,与对照相比,4个杜梨家系叶片膜透性在0.6%处理水平下均显著升高,其中LYG和QD14升幅较大,分别达到231.11%和238.97%,而YC和QD20的升幅较小,分别为67.77%和98.42%;4个杜梨家系叶片胞间二氧化碳浓度变化存在差异,随着盐处理水平升高,LYG和QD20呈先降低后升高的趋势,YC则一直降低,而QD14与YC相反。经因子分析和隶属函数分析,4个杜梨家系耐盐强弱依次为盐城>青岛14>青岛20>连云港。【结论】4个杜梨半同胞家系的耐盐性存在明显差异,盐城家系的综合耐盐能力最强,其次为青岛14和青岛20,连云港家系最弱。  相似文献   

7.
盐胁迫对乌桕幼苗光合特性及叶绿素含量的影响   总被引:7,自引:0,他引:7  
应用盆栽试验研究了不同盐(NaCl)胁迫下乌桕1年生幼苗光合特性与叶绿素指标的变化。结果表明:随着盐胁迫的加剧,GC2种源净光合作用速率(Pn)先上升后下降,其余种源Pn则随胁迫的加剧逐渐递减;在020 %(NaCl质量分数)盐胁迫下,与对照相比XN1与GC2两种源气孔导度(Gs)增大,其余种源Gs呈不同程度降低,按照降幅大小排序为:HS1、HZ2、GCH1、SC4。在质量分数为040 %与060 %的盐胁迫下,各种源Gs普遍低于对照;不同盐胁迫下各种源胞间CO2浓度(Ci)变化趋势不同;GC2、GCH1与HZ2种源叶绿素含量随盐胁迫的增加而下降,但XN1、SC4与HS1种源呈无规律变化。相关分析表明,Pn与Gs、Ci、Tr呈极显著正相关(p<001),但与叶绿素指标的相关性不明显。依据幼苗光合速率降幅与叶绿素含量变化分析,在轻度盐胁迫下XN1与GC2具有较强的忍耐性,SC4与GCH1次之,而GC2种源在中度盐胁迫下仍能维持一定的光合作用,其耐盐能力最强。  相似文献   

8.
水分胁迫对枣叶片光合作用和保护酶活性的影响   总被引:1,自引:0,他引:1  
以枣为试材,在大田滴灌条件下采取控水试验,研究不同水分处理对枣树光合作用和保护酶活性的影响。结果表明,各处理的蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci)日变化规律一致:Tr呈双峰曲线,Gs先上升后下降,Ci先下降后上升;对照(CK)和轻度水分胁迫(Ⅰ)的净光合速率(Pn)和Tr呈双峰曲线,重度水分胁迫(Ⅱ)下"双峰"和"午休"现象消失;随着水分胁迫的加剧,枣树叶片的Pn、Tr、Gs和Ci均下降,枣叶片中的过氧化氢酶(CAT)、超氧化物歧化酶(SOD)活性及丙二醛(MDA)含量均升高,过氧化物酶(POD)活性在轻度水分胁迫下升高,在重度水分胁迫下,活性降低。综合各项指标测定,轻度胁迫处理的灌溉周期为不影响枣生长及生产的节水灌溉策略。  相似文献   

9.
以引种于干热河谷典型地区元谋的沙漠葳(Chilopsis linearis)为研究对象,测定其旱季水势、叶片保水能力、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Cond)、胞间CO2浓度(Ci)等生理指标的日动态变化。结果表明:在干旱胁迫下,沙漠葳植株通过降低水势以有效地从土壤中吸取水分;沙漠葳叶片失水曲线总体平缓,水分保持能力强;其光合日进程曲线为双峰曲线,在一天中温度、光照和水分条件恶劣的14:00左右仍具有一定的光合能力。耐旱生理研究与田间生长观察表明,沙漠葳可适应干热河谷的恶劣气候并能正常生长。  相似文献   

10.
采用盆栽实验研究了不同聚丙烯酰胺用量下较短时间内CO2浓度升高对1年生胡杨叶片光合和水分和用效率的影响。结果表明:(1)随着聚丙烯酰胺用量的减少,土壤水吸力上升,干旱胁迫加重。叶片水势、净光合速率(Pn)、水分利用效率(WUE)、气孔导度(Gs)、蒸腾速率(Tr)随着干旱胁迫的加重而降低,胞间CO2浓度(Ci)则呈上升趋势。(2)随着CO2浓度的升高,各处理的胡杨叶片Pn、WUE、Ci上升,Tr、Gs下降。由此说明:CO2浓度升高对胡杨叶片Pn和WUE的促进作用在一定程度上能缓解干旱胁迫作用;聚丙烯酰胺用量大时,CO2浓度升高对胡杨Pn的促进作用较好;随着外界CO2浓度的升高,气孔关闭,蒸腾速率降低,从而增加了胡杨WUE,这将加强胡杨的耐旱能力。  相似文献   

11.
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.  相似文献   

12.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

13.
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.  相似文献   

14.
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。  相似文献   

15.
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  相似文献   

16.
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  相似文献   

17.
18.
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.  相似文献   

19.
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).  相似文献   

20.
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.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号