12种苜蓿叶片表面微形态结构的比较

应用扫描电子显微镜对苜蓿的12个品种叶片表面气孔、表皮毛和蜡质微形态进行了观察比较.结果显示:不同品种苜蓿叶片表皮气孔开度和密度﹑表皮毛长度和密度、蜡质形态均有较大的差异.4、7和11号品种上下表皮气孔开度比较小;除4号品种叶片的上表皮有表皮毛外,其它品种均无表皮毛的存在,4、5、12号品种的下表皮毛密度较大、表皮毛较长;不同品种苜蓿的上表皮均有蜡质覆盖,且4、9和10号品种蜡质覆盖较密集,下表皮中只有2、4、5、6、7、9号品种存在蜡质,且2、5、6和7号品种蜡质覆盖较密集,叶片表面蜡质出现线状、螺旋桨状、垂直片状、网状和棒状5种形态.气孔的开度和密度及表皮毛的长度和密度、蜡质的分布与苜蓿的抗旱性强弱存在一定的相关性.     

6个灰楸无性系叶片表皮微形态特征比较

为加快灰楸高抗品种选育进程,优化灰楸引种栽培管理方案.本研究采用扫描电镜技术对灰楸6个无性系叶片表皮微形态进行了观察.结果表明:灰楸无性系间表皮蜡质纹饰特征、蜡质纹饰分布量、气孔器类型、气孔器尺寸等微形态特征均有较大差异.07027、07028和07069无性系气孔器长度和宽度均较大,07027和07069无性系蜡质纹饰呈细条状,且分布量明显小于其他系号.07032和07040无性系气孔尺寸和开度较为适中,蜡质纹饰呈皱褶粗条状,大量密集于气孔器周围.此外,07032和07040无性系具有明显的气孔下陷特征.07029无性系气孔尺寸显著最小,蜡质纹饰分布较多,但非腺毛分布较为稀疏.根据与抗性相关的叶片解剖形态特征综合评价了灰楸无性系抗逆性,发现07032和07040无性系叶片微形态表现出优良的抗旱或抗寒能力,初步认为07032和07040无性系为灰楸优良高抗无性系.     

木立芦荟发育过程中叶表皮角质膜和蜡质的变化

应用扫描电镜观察了不同发育阶段的木立芦荟叶表面角质膜、蜡质的形态结构。结果显示,在木立芦荟叶发育的早期,叶表面只有一层薄的角质膜,没有蜡质。随着叶的发育,角质膜逐渐增厚,在角质膜表面逐渐形成瘤状蜡质突起。当叶发育成熟时,表面覆盖有厚的角质膜,角质膜上分布有密集的瘤状蜡质。在叶表皮上分布有下陷的气孔,气孔上方的角质膜和蜡质呈筒状围绕在气孔四周。由于木立芦荟叶表气孔下陷,又覆盖着厚的角质膜和密集的蜡质．能有效地减少水分散失和增强叶片反射光辐射的能力,因此,芦荟能适应干旱、强光照的环境。     

草甘膦导致板栗叶片形态畸形的扫描电镜观察

除草剂应用不当会影响板栗的正常生长发育,本文分析了过量草甘膦喷洒后对板栗不同成熟度叶片形态的影响。实验利用扫描电镜观察对喷洒过除草剂的不同发育程度的板栗叶片及对照叶片下表皮显微结构进行分析,结果表明:从表型上看,没有喷洒草甘膦的对照板栗叶片正常,而喷洒除草剂后的板栗叶片卷曲皱缩,致畸等;从超微结构看,对照叶片的下表皮布满腺毛,因而不能观察到表皮结构及气孔等。喷洒除草剂的板栗叶片的下表皮腺毛不饱满,萎蔫,甚至无腺毛,可以观察到表皮结构及气孔,不同发育时期的气孔密度不同。过量草甘膦导致板栗叶片形态畸形。     

扫描电镜下9种卷柏叶表皮特征的系统学意义

应用扫描电镜观察卷柏属(Selaginella)9种植物的叶表皮。结果显示:表皮细胞长条形或不规则多边形;垂周壁平直或波状;叶缘具或不具明显的刺结构;表皮细胞附属有鳞片状、颗粒状及瘤状突起等;气孔器多为不规则型,其大小、数量、分布及孔口是否光滑,气孔带是否有瘤状突起分布等特征在不同种间存在差异,尤其对卷柏属植物的表皮附属物瘤状突起进行了细致的观察,统计并测量其类型、分布、数量及大小,首次将其应用于卷柏属植物的分类鉴定中。为探讨种间亲缘关系提供更具针对性的微形态学资料。     

桉树叶片的解剖结构与其对焦枯病抗性的关系

选取福建省11个桉树(Eucalyptus spp)主栽种系中对焦枯病(Clindrocladium quinqueseptatum)的高抗种系巨赤桉9224和高感种系巨桉5号进行叶片解剖结构特征研究,结果表明:(1)巨赤按9224的叶片蜡质含量明显高于巨桉5号,桉树叶片的蜡质层是抵抗和延迟病原茵侵入的最外层防线;(2)2种按树下表皮气孔密度与其抗痛性相关性小,而巨赤桉9224的气孔小,气孔下陷更深,不利于病原侵入,表现出抗性高;(3)巨赤桉9224的叶片比巨桉5号厚,表现为上下表皮角质层厚,栅栏组织细胞层数更多,栅栏组织,海绵组织比大,叶肉细胞排列更紧密,可以抵抗病菌的侵入和扩展,成为抗病的又一个结构屏障;(4)巨赤桉9224的叶绿体数量多,累积淀粉多,抗性也随之增强.据此可以把桉树叶片蜡质含量作为鉴定桉树种系抗性的一种快速手段,桉树叶片厚度、栅栏组织厚度及其细胞排列紧密度作为桉树抗焦枯病的辅助指标.     

沙打旺栽培品种叶片的扫描电镜观察

沙打旺(Astragalus adsurgens pall.)即直立黄芪,原产我国,引种栽培始于我国,是一种优良的固沙、保土、饲料植物。具耐寒、抗旱等特性。目前还未见到有关沙打旺叶片的电镜观察指导。利用电镜对沙打旺叶片的表面和内部结构进行深入研究,将有助于更好地栽培、利用,可对耐寒、抗旱植物进行深入研究。我们用光镜和扫描电镜观察了沙打旺栽培品种的叶子表面。观察表明: 1.叶表面被丁字状着生毛,系两端尖锐而中部偏一端着生于叶表面的单细胞毛,“柄”极短几乎没有,毛紧贴于表面(见照片)。叶背面比叶正面分布多,背叶面叶脉上也有分布。毛的顺向与单叶主脉基本一致(照片略)。表毛面具较多的疣状突起呈无规则排列。     

桑寄生科蜡叶标本叶SEM样品的制备

采用常规方法制备新鲜植物叶片扫描电镜观察的样品。而对60-70年的蜡叶标本叶SEM样品制备，根据叶片的薄厚，革质程度进行处理。经过反复实验，本文对桑寄生科蜡叶标本叶经浸泡→水煮→离析法等程序，可清晰地看到叶表皮细胞的排列，气孔的形状；对气孔大小的测量、密度计算等，得到非常好的图像数据。     

番荔枝属不同品种叶表面微形态的电镜观察

应用扫描电子显微镜对番荔枝属九个番荔枝品种的叶表面角质、蜡质、表皮毛、气孔等微形态进行了观察比较.结果显示：它们之间的叶表面表皮毛、角质、蜡质和气孔等微形态均有较大的差异.秘鲁番荔枝、AP杂交番荔枝、无核番荔枝上下表面均具有单列丝状毛,气孔只分布于下表面;普通番荔枝、圆滑番荔枝、粗鳞番荔枝叶表面均无表皮毛;秘鲁番荔枝、AP杂交番荔枝、普通番荔枝、粗鳞番荔枝上下表皮角质呈不规则的岛状突起,而圆滑番荔枝、无核番荔枝表面角质较平,角质膜形状不甚清晰;以上所述番荔枝叶表面都覆盖有密厚的针晶状蜡被;除圆滑番荔枝的气孔有副卫细胞外,其它气孔只有保卫细胞而无副卫细胞;刺番荔枝、山刺番荔枝、牛心番荔枝的叶表皮毛为短棍棒状,其表皮角质细胞呈乳突状或波状突起;山刺番荔枝的棒状毛顶端钝圆,而刺番荔枝与牛心番荔枝的棒状毛顶端尖锐;刺番荔枝和山刺番荔枝只有下表皮才具有棒状毛,其气孔形状近似圆形,孔口略内陷于表皮层,牛心番荔枝表面角质呈不规则波状突起,气孔细长稍突.由于这些不同的叶表面微形态是长期受各物种原产地的气候、环境条件影响所形成的,因此研究番荔枝品种的叶表面微形态结构,对正确引种和推广番荔枝果树种植有着重要的意义.     

适用于扫描电镜的拟南芥蜡质样品制备方法

扫描电镜是观察植物表皮蜡质结构的极佳方法。由于蜡质成分不同,不同的植物有不同的样品干燥方法。本文以拟南芥叶片为实验材料,比较FAA固定和戊二醛－锇酸双固定,CO2临界点干燥和冷冻干燥,以及乙醇、乙酸异戊酯、丙酮和叔丁醇等不同的固定方法、不同的干燥方法和不同的有机溶剂对蜡质的溶解作用后,认为更适于拟南芥表皮蜡质观察的样品制备方法是：戊二醛－锇酸双固定,叔丁醇与乙醇梯度脱水,叔丁醇冷冻干燥。     

肉豆蔻科（Myristicaceae）3属国产种类的叶表皮形态观察

利用光学显微镜和扫描电子显微镜观察了肉豆蔻科（Myristicaceae）国产3属9种植物的叶表皮,研究各种的叶表皮细胞形状及垂周壁式样、表皮蜡质纹饰及表皮毛的具体特征,测量并统计了气孔器类型、气孔密度等指标。结果显示：所观察的种类表皮细胞排列都很整齐,表皮细胞多边形或不规则形,垂周壁垂直或呈波状。表皮细胞覆盖角质层且仅远轴面具气孔,气孔器类型多为平列型,2～5个副卫细胞,在红光树属发现4气孔或5气孔集生的现象;有些种具星状毛。肉豆蔻科植物气孔器、角质层纹饰和表皮毛特征在属之间差异比较明显,可以作为划分属的重要依据,具有重要的分类学意义。     

Very high density interconnect elastomer chip sockets

The integration of more and more functionality into smaller and smaller form factor electronic products, drives the need for denser chip to substrate interconnect systems. As the number of I/O pins increases, the use of area array chips or packages becomes inevitable. Metal patterned elastomer chip sockets have now been improved to work with contact densities as high as 80 000 contacts/cm/sup 2/ corresponding to a pitch of 36 /spl mu/m. Sockets with 10 000 contacts and a 72-/spl mu/m pitch have survived more than 400 cycles in air-to-air thermal cycling chambers as well as freezing shocks caused by dipping into liquid nitrogen. Although the daisy chain test circuits breaks for temperatures lower than -50/spl deg/C and higher than 90/spl deg/C, they always return to the initial resistance values when entering the normal temperature range. The combination of a gold-to-gold contact interface and the elastic features of the contact bumps makes this socket an ideal compliance layer between bare chips and different types of carrier substrates, reducing the problems caused by thermomechanical mismatch between the substrate and the chip. Bad dies can easily be replaced, since the chip is not soldered or glued to the socket. The size and the possibility to control the geometry of the contacts provides means to maintain a good high-frequency characteristic impedance matching all the way to the chip pad.     

Effect of bump size on current density and temperature distributions in flip-chip solder joints

Three dimensional thermo-electrical analysis was employed to simulate the current density and temperature distributions for eutectic SnAg solder bumps with shrinkage bump sizes. It was found that the current crowding effects in the solder were reduced significantly for smaller solder joints. Hot-spot temperatures and thermal gradient were increased upon reducing the solder. The maximum temperature for solder joint with 144.7 μm bump height is 103.15 °C which is only 3.15 °C higher than the substrate temperature due to Joule heating effect. However, upon reducing the bump height to 28.9 μm, the maximum temperature in the solder increased to 181.26 °C. Serious Joule heating effect was found when the solder joints shrink. The higher Joule heating effect in smaller solder joints may be attributed to two reasons, first the increase in resistance of the Al trace, which is the main heating source. Second, the average and local current densities increased in smaller bumps, causing higher temperature increase in the smaller solder bumps.     

Effect of Grain Boundary Misorientation on Electromigration in Lead-Free Solder Joints

Reduction in microelectronic interconnect size gives rise to solder bumps consisting of few grains, approaching a single- or bicrystal grain morphology in C4 bumps. Single grain anisotropy, individual grain orientation, presence of easy diffusion paths along grain boundaries, and the increased current density in these small solder bumps aggravate electromigration. This reduces the reliability of the entire microelectronic system. This paper focuses on electromigration behavior in Pb-free solder, specifically the Sn-0.7 wt.%Cu alloy. We discuss the effects of texture, grain orientation, and grain boundary misorientation angle on electromigration (EM) and intermetallic compound formation in EM-tested C4 bumps. The detailed electron backscatter diffraction (EBSD) analysis used in this study reveals the greater influence of grain boundary misorientation on solder bump electromigration compared with the effect associated with individual grain orientation.     

黑龙江苹果亚科植物叶表皮形态结构的研究

利用扫描电子显微镜对黑龙江苹果亚科14种植物叶表皮微形态进行比较研究。结果显示:(1)叶表皮细胞呈多边形或无规则形,垂周壁式样呈平直或弓形、浅波纹、深波纹;(2)除无毛花楸无表皮毛外,其它均具有表皮毛,类型均为单细胞不分支非腺毛;(3)叶表皮纹饰呈均匀分布蜡质纹饰和仅气孔周围有蜡质条纹;(4)气孔器均在下表皮分布,且气孔器类型为轮列型、无规则型或不典型辐射型;气孔外拱盖为单层或双层,内缘近平滑或不规则波状;保卫细胞两极仅在水榆花楸、毛山楂、黑果栒子和全缘栒子中出现"T"型加厚。研究表明,该亚科下5属间的叶表皮微形态特征存在一定差异,属内种间在气孔器、表皮毛以及表皮纹饰特征上存在一致性,为属间的系统分类和演化提供了形态结构的依据。     

Eutectic Sn-Ag solder bump process for ULSI flip chip technology

A novel eutectic Pb-free solder bump process, which provides several advantages over conventional solder bump process schemes, has been developed. A thick plating mask can be fabricated for steep wall bumps using a nega-type resist with a thickness of more than 50 μm by single-step spin coating. This improves productivity for mass production. The two-step electroplating is performed using two separate plating reactors for Ag and Sn. The Sn layer is electroplated on the Ag layer. Eutectic Sn-Ag alloy bumps can be easily obtained by annealing the Ag/Sn metal stack. This electroplating process does not need strict control of the Ag to Sn content ratio in alloy plating solutions. The uniformity of the reflowed bump height within a 6-in wafer was less than 10%. The Ag composition range within a 6-in wafer was less than ±0.3 wt.% Ag at the eutectic Sn-Ag alloy, analyzed by ICP spectrometry. SEM observations of the Cu/barrier layer/Sn-Ag solder interface and shear strength measurements of the solder bumps were performed after 5 times reflow at 260°C in N₂ ambient. For the Ti(100 nm)/Ni(300 nm)/Pd(50 nm) barrier layer, the shear strength decreased to 70% due to the formation of Sn-Cu intermetallic compounds. Thicker Ti in the barrier metal stack improved the shear strength. The thermal stability of the Cu/barrier layer/Sn-Ag solder metal stack was examined using Auger electron spectrometry analysis. After annealing at 150°C for 1000 h in N₂ ambient, Sn did not diffuse into the Cu layer for Ti(500 nm)/Ni(300 nm)/Pd(50 nm) and Nb(360 nm)/Ti(100 nm)/Ni(300 nm)/Pd(50 nm) barrier metal stacks. These results suggest that the Ti/Ni/Pd barrier metal stack available to Sn-Pb solder bumps and Au bumps on Al pads is viable for Sn-Ag solder bumps on Cu pads in upcoming ULSIs     

榛属植物花粉形态扫描电镜观察

目的:为榛属植物的系统分类学提供孢粉学证据,明确榛属植物花粉形态特征及其与品种分类、系统进化的关系.方法:采用一致的方法培育植物材料并收集花粉,以14份不同种(品种)的榛属植物花粉为材料,使用FAA固定液固定,二氧化碳临界点干燥法处理花粉,在扫描电子显微镜下观察花粉的形状、大小、萌发孔距、萌发孔径比和表面纹理等指标,并进行聚类分析.结果:榛属植物的花粉为单粒花粉,多为3萌发孔,萌发孔分布在赤道面上,属于N3 P4 C4类型;花粉形状为近扁球形,极面观为三角形,赤道面观为椭圆形,花粉外壁纹饰为皱波状和刺状,不同种(品种)的花粉在大小、皱波明显度、刺的大小和密度上存在差异;对上述指标进行聚类分析,将14份样品聚为3类.第1类:华榛、绒苞榛、川榛、'辽榛3号'、'达维'、'Casina'和'Ennis',属于中等大小花粉,皱波不明显;第2类:平榛'JMS'、'HLP'、'WC'和毛榛,花粉表面皱波不明显,刺较小且致密;第3类:藏刺榛、'Maria'和'辽榛7号',花粉表面皱波明显,刺的分布密度较疏.结论:榛属植物的花粉在大小、外壁皱波纹饰、刺的大小和密度方面差异较大,可为榛属植物的种属分类和品种鉴定提供孢粉学依据;本研究的取样和实验方法也可为其他相关研究提供参考.