首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 91 毫秒
1.
大豆珠柄传输组织的显微形态观察   总被引:1,自引:1,他引:0  
大豆光合作用产物是以淀粉粒的形式暂时贮存在叶片和豆荚的叶绿体中,以后在特定的时期降解为可溶性糖(碳水化合物)转移到需要的部位。这种光合产物的转移主要是在植物的维管组织中实现。在大豆植株生长的鼓粒期和成熟期,豆荚中还原糖的含量明显高于叶片。但由于豆荚的叶绿素含量及  相似文献   

2.
大豆豆荚的扫描电镜观察   总被引:5,自引:2,他引:3  
大豆在结荚鼓粒期叶片的光合速率与籽粒产量呈显著正相关性。而大豆豆荚光合作用及其与籽粒生长发育关系的研究则极少见报。因此在幼荚期、鼓粒期和成熟期,研究大豆荚果的形态发生、发育机理及豆荚对籽粒生长的供需关系,对提高大豆产量及高光效大豆品种的选育具有十分重要的意义。  相似文献   

3.
Rubisco及其活化酶定位于豌豆和蚕豆叶绿体中   总被引:1,自引:1,他引:0  
运用免疫金标记电镜技术研究了豆科C3植物豌豆(Pisum saticum L.)和蚕豆(Vicia faba L.)叶片中Rubisco及其活化酶(RCA)的细胞定位,结果表明:两种植物叶片解剖结构及叶绿体超微结构相似,叶肉细胞叶绿体具有发达的基粒片层,Rubisco和RCA免疫金标记颗粒主要分布于叶绿体的间质中,在基粒片层上很少,在表皮的气孔保卫细胞叶绿体内也有免疫金颗粒标记,在细胞质、液泡、线粒体等细胞器中无特异性标记。两种植物光合作用关键酶在叶绿体中定位的相似性,体现了C3植物在光合器结构与功能上具有共性。  相似文献   

4.
为探究发育期黄果肉桃果实质体发育情况,以黄肉桃‘23-40’为研究对象,对发育期桃果实,分别采用分光光度法测定色素变化,冷冻切片法观察质体的形态,Mini?Imaging?PAM叶绿素荧光成像仪测定不同区域叶绿素荧光。结果表明:(1)随着果实发育,光合色素组分处于动态变化之中,叶绿素a( Chl. a)、叶绿素b( Chl. b)含量、Chl. a/b和Chl.(a+b)/Car.(类胡萝卜素)均下降,而类胡萝卜素(Car.)和花青素(Ant.)含量上升。(2)盛花后65天,桃果实表皮下第4~12层果肉细胞分布大量叶绿体,且叶绿体数量由外向内逐渐减少;随着发育,叶绿体体积缩小,数量下降,类胡萝卜素的积累使质体由绿色向黄色转变,果实成熟后,质体类囊体解体,叶绿体转化为有色体。(3)随着果实发育,桃中果皮捕光能力和光合潜力逐渐减弱,叶绿体的光能利用效率先上升后下降;且果实中果皮外侧的荧光活性比内侧强,成熟桃果实中果皮基本不具备光合能力。这些结果暗示黄肉桃发育过程中色素成分含量、质体形态分布和光合能力具有时空差异。  相似文献   

5.
‘麦香’桃叶片变色期色素含量及超微结构的变化   总被引:1,自引:0,他引:1  
本文以桃的栽培品种‘麦香’(Prunus persica‘mai xiang’)为试材,在8月中旬其叶片由绿变紫红时,对其不同叶位的叶片色素含量进行了测定;以叶色维持绿色不变的品种‘照手姬’桃(Prunus persica‘terutehime’)为对照,并观察了这2个品种的叶片细胞超微结构。结果表明:当花色苷与总叶绿素、类胡萝卜含量的比值约为1∶3.86∶0.43时叶片开始转为淡紫色;当三者含量的比值达到1∶1.70∶0.18时,‘麦香’的整个叶片转变为紫色;当三者的比值大于1∶1.35∶0.16时,叶片的紫色加深变为紫红色。超微结构研究发现,‘麦香’的顶端嫩叶与‘照手姬’的存在显著差异,‘照手姬’桃叶绿体基粒片层清晰,而此时‘麦香’叶绿体基粒片层已表现出明显的松散,线粒体膜有降解现象,而且在上表皮细胞和栅栏组织的液泡中已存在不明物质,这种幼龄期表现的衰老迹象,可能是‘麦香’桃的早熟性决定的。在基部叶片的超微结构中,两品种都出现了相似的衰老现象,即叶绿体片层结构严重扭曲并出现解体现象、嗜锇颗粒增多变大、线粒体外膜解体,内嵴混乱。此外’麦香’叶片中还显示出特有的结构:栅栏组织细胞的液泡和上表皮细胞出现大量絮状或粒状的黑色物质。本实验结果表明,‘麦香’桃叶片的成色取决于花色苷和总叶绿素的比例,‘麦香’桃在变色期合成花色苷,然后可能运输到栅栏组织的液泡和上表皮细胞,使叶片呈现紫红色。  相似文献   

6.
几个不同种源的黑荆树在冰冻后叶片细胞超微结构的研究   总被引:8,自引:0,他引:8  
本文报道了6个不同种源的黑荆树枝条在-5℃冰冻10小时后,其叶片细胞超微结构的变化。观察结果表明:1和B种源的叶片细胞超微结构受到严重和较严重的破坏,其叶绿体解体,类囊体空泡化,线粒体内嵴也遭到破坏,这些变化是不可逆的;而C1、C5、C3、C4黑荆种源,其叶细胞中的叶绿片层排列方向虽发生了改变,但叶绿体外膜仍保持完好,百这些变化则是可逆的。  相似文献   

7.
叶绿体是真核光合生物特有的细胞器 ,要研究叶绿体的光合作用 ,首先得了解其结构及在细胞内的分布状况。国内外学者在六七十年代就曾在显微、亚显微水平上作过较系统的观察[2、3] ,左宝玉等 ( 1 978)曾经对冬小麦不同层次叶片中叶绿体超微结构及其功能作过详细报道[1] 。在同一环境中生长的小麦 ,产量有高有低。利用石蜡切片技术对小麦旗叶进行扫描电镜观察[4 ] ,将从形态学角度揭示小麦旗叶中叶绿体与粒重和产量的关系 ,为育种和栽培小麦提供理论依据。材料与方法1 .材料 供试小麦为 :黑引一号 ( Triticum aestivum L.CV Heiyin1 ,春性…  相似文献   

8.
水稻叶片表面结构电镜观察   总被引:1,自引:1,他引:0  
本文以农S-1水稻光温敏不育系倒数第二叶的功能叶片为材料对水稻叶片表面结构进行了电镜观察,结果表明叶片表皮细胞上着生有长毛、钩毛、刺毛、纤细毛和锯齿毛等茸毛。长毛和钩毛着生于硅质化和木栓化的细胞列上,刺毛和纤细毛着生于硅质化、木栓化细胞列与气孔区之间的普通表皮细胞上。锯齿毛着生于叶片边缘。  相似文献   

9.
小麦不同发育时期旗叶叶绿体结构与多糖的动态变化   总被引:3,自引:1,他引:2  
以往有关小麦旗叶的研究多集中在生理生化方面,对不同时期旗叶的生理生化特性及其叶片结构动态变化的研究尚不多见.本文应用光学显微镜、透射电子显微镜、显微组织化学和紫外分光光度计等技术和方法,对高产小麦品系(小偃81)开花前后旗叶叶绿体数目与超微结构变化,以及多糖的显微定位与含量等进行了研究.结果表明:小麦旗叶叶肉细胞中的叶绿体数目、叶绿体基粒类囊片数目和垛叠数随着小麦开花期的到来逐渐增多,至开花后的灌浆期均达最高值,此后随之明显下降.与此同时,多糖与蔗糖含量等也有相似的变化趋势.我们认为:在小麦开花前后,特别是灌浆期,旗叶上述特征与小麦的光合效率及产量关系极为密切.本文的观察结果为高产小麦的选育和栽培管理提供了参考依据.  相似文献   

10.
本实验以分属早熟和晚熟两类不同抗冷级别的3个棉花品种为材料,将其幼苗经4℃低温处理12h,用透电子显微镜观察叶片细胞超微结构的变化。结果表明:低温处理后早熟品种的叶绿体和液泡没有明显的变化;而晚熟品种的叶绿体则发生变形重叠,液泡浓度加大,且出现了多层膜状结构。说明细胞结构的稳定性与棉花品种的抗冷性密切相关。  相似文献   

11.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

12.
IntroductionNanoimprint Lithography is a well-acknowl-edged low cost, high resolution, large area pattern-ing process. It includes the most promising methods,high-pressure hot embossing lithography (HEL) [2],UV-cured imprinting (UV-NIL) [3] and micro contactprinting (m-CP, MCP) [4]. Curing of the imprintedstructures is either done by subsequent UV-lightexposure in the case of UV-NIL or by cooling downbelow the glass transition temperature of the ther-moplastic material in case of HEL…  相似文献   

13.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

14.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.  相似文献   

15.
A doping system consisting of NPB and PVK is employed as a composite hole transporting layer (CHTL). By adjusting the component ratio of the doping system, a series of devices with different concentration proportion of PVK : NPB are constracted. The result shows that doping concentration of NPB enhances the competence of hole transporting ability, and modifies the recombination region of charge as well as affects the surface morphology of doped film. Optimum device with a maximum brightness of 7852 cd/m^2 and a power efficiency of 1.75 lm/W has been obtained by choosing a concentration proportion of PVK : NPB at 1:3.  相似文献   

16.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

17.
Due to variable symbol length of digital pulse interval modulation(DPIM), it is difficult to analyze the error performances of Turbo coded DPIM. To solve this problem, a fixed-length digital pulse interval modulation(FDPIM) method is provided. The FDPIM modulation structure is introduced. The packet error rates of uncoded FDPIM are analyzed and compared with that of DPIM. Bit error rates of Turbo coded FDPIM are simulated based on three kinds of analytical models under weak turbulence channel. The results show that packet error rate of uncoded FDPIM is inferior to that of uncoded DPIM. However, FDPIM is easy to be implemented and easy to be combined, with Turbo code for soft-decision because of its fixed length. Besides, the introduction of Turbo code in this modulation can decrease the average power about 10 dBm, which means that it can improve the error performance of the system effectively.  相似文献   

18.
It is a key problem to accurately calculate beam spots' center of measuring the warp by using a collimated laser. A new method, named double geometrical center method (DGCM), is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device (CCD) is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What's more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.  相似文献   

19.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

20.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  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-23

京公网安备 11010802026262号