家蚕血细胞对病原微生物吞噬作用的扫描电镜观察

为探讨家蚕血细胞的吞噬作用,对蚕体腔分别注射微粒子孢子M_(1 2)和核多角体,经30min、1h、2h后,用相差显微镜及扫描电镜进行观察。家蚕血细胞对微粒子M_(1 2)孢子及核多角体的捕食作用,主要为颗粒细胞,其吞噬作用较之其他血细胞显著,家蚕血细胞对微粒子及核多角体的吞噬作用主要为膜捕捉(active en-membranosis),注射病原微生物30min后,可观察到多数的颗粒细胞已在捕食病原微生物;经2h后,多数的颗粒细胞已吞噬了数个甚至10数个病原微生物。

扫描电镜在金属材料方面的应用

介绍了扫描电子显微镜的原理及特点,阐述了扫描电镜及能谱仪在产品质量控制,濟偏析的检验,质量事故分析,组织确定、失效分析等方面的应用,说明了扫描电子显微镜对金属衬料科学发展的贡献。

国人胆囊结石的形态结构特征

目的:探讨胆囊结石中晶体物质的组成、形态和结构及其在胆囊结石形成与生长过程中的作用。方法:在单盲的条件下,分别用偏光显微镜、扫描电镜和X射线衍射仪对35例人体胆囊结石的晶体结构、剖面超微结构及晶体组成进行观察研究。结果:颗粒状胆囊结石尽管其外观和剖面的形状结构各不相同,但都以结晶矿物质为主,其主要成分为胆固醇晶体。晶体的干涉色级为二级蓝绿,双折射率△n=0.022-0.025。胆石中的晶体以密集分布的微晶体和微晶体集合体的形式存在,其间隙被非晶物质填充,泥沙状结石以非晶态物质为主,其主要成分是胆色素和胆色素盐,属胆色素结石。结论:人体胆囊结石是一种特殊的生物晶体。胆囊内多变的结晶环境并不支持胆固醇晶体的完整发育,胆固醇晶体构成了颗粒状胆囊结石的基本架构,非晶物质的沉积促使了结石的进一步生长。

Micro-galvanic corrosion behaviour of Mg-(7,9)Al-1Fe-xNd alloys

The localized micro-galvanic corrosion process and the kinetic information of Mg-(7,9)Al-1Fe-x Nd alloys were investigated by in situ observation under electrochemical control and in situ atomic force microscopy(AFM)in an electrolyte environment.The results revealed that the formation of the Nd-rich phase in alloys resulted in a decrease in the Volta potential difference from~400 m V(AlFe3/α-Mg)to~220 mV(Nd-rich/α-Mg),reducing the corrosion products around the cathodic phase and corrosion current density of the microscale area.The addition of Nd significantly improved the corrosion resistance,mainly due to the suppression of the micro-galvanic corrosion between the second phases and substrate.Finally,the corrosion mechanism of Mg-(7,9)Al-1Fe-x Nd alloys was discussed based on in situ observations and electrochemical results.

Fracture characteristics of notched investment cast TiAl alloy through in situ SEM observation

TiAl alloys were produced by investment casting method combined with induction skull melting （ISM） technique. In situ scanning electron microscopy （SEM） was utilized to study the fracture characteristics and crack propagation of a notched investment cast TiAl specimens in tension under incremental loading conditions. The whole process of crack initiation, propagation and failure during tensile deformation was observed and characterized. The results show that the fracture mechanism was sensitive to not only the microcracks near the notched area but also lamellar orientation to loading axis. The high tensile stress leads to the new microcracks nucleate along lamellar interfaces of grains with favorable orientation when local stress intensity reaches the toughness threshold of the material. Thus, both plasticity and high tensile stress are required to cause notched TiAl failure.

Scanning Electron Microscopy of Antennae of Aphidoletes aphidimyza (Diptera: Cecidomyiidae)

The morphology of antennae of Aphidoletes aphidimyza was observed with a scanning electron microscope. The results showed that both male and female were fourteen segmented, the male was approximately 2000 μm and the female was 1050μm. Six types of sensillae on the antenna were observed, viz. chaetica （Ch）, trichoidea （Tr）, basiconica （Ba）, cavity （Ca）, styloid （St） and circumfila （Ci） on the antennae of A. aphidimyza. Sensillae Ch had a long external-process, with a base surrounded by membranous sockets and a length of about 67.5 μm. Sensillae Tr were distally curved and inserted into a depression, 61.0μm long. Sensillae Ba were peg-like and 4.7μm long on the antennae. Sensillae Ca were pit-like in appearance and the diameter of the pit was 1.2μm. Sensilla St was found on the second sub-segment flagellum of the male antennae. The length of the sensilla was about 21 μm and the diameter was 1.5μm. The circurnfila, which are a unique type of sensilla found only on cecidomyiid antennae, formed loops around each of the antennal sub-segments, and were attached to the surface by a series of stalks. Sensilla St was only present on male antenna. The number of Ba and Tr was almost the same in both sexes. There were more Sensilla Ca on the male antenna than on the female, while there was more Ch on the female.

Scanning Electron Microscope Observation of Three Species on Pollen Grain Morphology and Leaf Epiderm Shape in Gramineae Triticeae

The pollen grain morphology and leaf epiderm shape and microstructural of Rye（ Secale cereal ）, common wheat and Octoploid Trititrigia were observed with the scanning electron microscope（SEM）. The results revealed that there were great differences between pollen and leaf epiderm microcosmic morphology in three species. Such characteristics of Octoploid tnticalwere between those of common wheat and Rye. The morphology of pollen grain and leaf epiderm shape counld be used as an index for taxonomy for genera and species, and had somewhat scientif- ic references to identify new multiploid species created by chromosome engineering.

Development of advanced electron tomography in materials science based on TEM and STEM

The recent developments of electron tomography（ET） based on transmission electron microscopy（TEM） and scanning transmission electron microscopy（STEM） in the field of materials science were introduced. The various types of ET based on TEM as well as STEM were described in detail, which included bright-field（BF）-TEM tomography, dark-field（DF）-TEM tomography, weak-beam dark-field（WBDF）-TEM tomography, annular dark-field（ADF）-TEM tomography, energy-filtered transmission electron microscopy（EFTEM） tomography, high-angle annular dark-field（HAADF）-STEM tomography, ADF-STEM tomography, incoherent bright field（IBF）-STEM tomography, electron energy loss spectroscopy（EELS）-STEM tomography and X-ray energy dispersive spectrometry（XEDS）-STEM tomography, and so on. The optimized tilt series such as dual-axis tilt tomography, on-axis tilt tomography, conical tilt tomography and equally-sloped tomography（EST） were reported. The advanced reconstruction algorithms, such as discrete algebraic reconstruction technique（DART）, compressed sensing（CS） algorithm and EST were overviewed. At last, the development tendency of ET in materials science was presented.

Comparative Study on Morphological Characteristics of Ova from Two Species in Noctuidae

[Objective] The aim was to explore the morphological characteristics of ovum from Spodoptera exigua and Heliothis assulta.[Method]The ultra morphological characteristics of ovum was observed with scanning electron microscope（SEM）.[Result]The ova from S.exigua and H.assulta are all spheroid,the former has net line decoration on surface,with some aeropyle distributed on the net line decoration;the micropyle is located in the center of polar and has plum flower-like engraving;the surface of chorion of the latter has the parallel crowns through two polar.Between the parallel crown,the surface of chorion has the decorated trapezium line,all crowns of second polar zone have breast-tuber that distributes in parallel at the same latitude in line,and there is no aeropyle distributing on chorion.[Conclusion] The ultra morphological characteristics of the ova from two Noctuidae species showed significant difference to each other,which enriched ontogenesis data and also provided reference for the accurate identification of two kinds of ova.

Observation and Comparision on Morphological Characteristics of the Seed-like Fruits of Salvia shandongensis and Its Relatives

[Objective] This study aimed to compare and analyse the morphological characteristics of the seed-like fruits between Salvia shandongensis J. X. Li et F. Q. Zhou and its relatives. [Method] The morphological characteristics of the mature seed-like fruits of Salvia shandongensis and its three congeners, S. miltiorrhiza, S. miltiorrhiza f. alba and S. bowleyana, were comparatively observed using both optical microscope and scanning electron microscope. [Result] The results showed that there were distinct differences in the shape, size and exine sculpture of the seed-like fruits of the four Danshen congeners： the seed-like fruits of S. shandongensis that were elliptical and had areolate sculpture with subquadrangular convex meshes as well as densely filamentous transverse lines were easy to be distinguished from those of S. miltiorrhiza Bge., which were broadly elliptical and had reticulate sculpture with subquadrate concave meshes. The seed-like fruits of S. bowleyana were fusiform and their ektexine had reticulate sculpture with polygonal meshes, which were slightly convex at the center, which are obviously different from those of S. shandongensis. [Conclusion] This study first accumulates data of the seed-like fruits of S. shandongensis, which provides important bases for establishing its taxonomical status and studying its germplasm. The morphological characteristics and reticulate sculpture on ektexine of the seed-like fruits S. miltiorrhiza Bge. are consistent with the previous report. The results in this study not only provide references for uncovering the genetic relationships between S. shandongensis and S. miltiorrhiza Bge., as well as the interspecific classification and identification. In addition, this study also provides new scientific proofs for the identification of Danshen species and their introduction and cultivation, genetics and breeding.

Nature,Characteristics and Uitrastructure Observation of Fibers of Seven Kinds of Special Animals

[Objective]Aimed to study the nature,characteristics and ultrastructure of fibers of Ovis aries and several kinds of special animals.[Method]Wool,cashmere,alpaca,Bactrian camel hairs,rabbit hair,mohair and yak hair were used as the experimental materials,and scanning electron microscopy was used to observe their scale structure.[Result]The rake angle of wool was large with an average of 33.2°,the scale density was 16.2-34.9 scales/mm,the average height of scale was 12.95 μm,and the average thickness was 0.63 μm;the rake angle of cashmere was smaller than wool with an average of 20.6°,the scale density was of 10.3-15.6 scales/mm,the scale distance was large,the average height of scale was 16.09 μm,and the average thickness was 0.46 μm;the average rake angle of alpaca was 34.6°,with the average scale height of 5.85 μm,and average thickness of 0.33 μm;the average rake angle of camel hair was 33.5°,with the average scale height of 11.30 μm and average thickness of 0.37 μm;the average rake angle of rabbit hair was 31.2°,with average scale height of 7.03 μm and average thickness of 0.36 μm;the rake angle value of mohair was between wool and cashmere,and the average of which was 23.7°,the scale density value was also between the wool and cashmere,with the average scale height of 15.82 μm and average thickness of 0.61 μm;the average rake angle yak hair was 33.2°,with the average height of 9.08 μm and average thickness of 0.46 μm.[Conclusion]The results of this study could provide a basis for the identification of different fiber types.

Antagonistical Mode of Pichia membranefaciens to Rhizopus stolonifer in Wounds of Peach Fruit

膜醭毕赤酵母 (PichiamembranefaciensHansen)是本实验室从果实上分离获得的一种能有效防治桃果实采后软腐病的拮抗菌。本文将P .membranefaciens与葡枝根霉 (Rhizopusstolonifer)在桃果实伤口部位共培养 2 4h后 ,用扫描电子显微镜观测了它们的拮抗作用。结果表明 ,在有病原菌的地方聚集了大量的酵母拮抗菌 ,而且拮抗菌紧密地吸附在病原菌的菌丝体上。结合以前的研究结果可以推断 ,P .membranefaciens主要通过与病原菌进行营养和空间的竞争 ,紧密地吸附在病原菌菌丝体上分泌能降解病原菌细胞壁的水解酶 (如几丁质酶和 β_1,3_葡聚糖酶 ) ,并可能诱导寄主产生抗性 ,从而抑制桃软腐病的发生。

Manufacturing of SEM and TEM Samples for Oocyte

[ Objective] The research aimed to explore the manufacturing methods of scanning electron microscope （SEM） and transmission electron microscopy （TEM） for oocyte and provide technical support for related research. [ Method] Based on GV-and MII-stage oocytes, samples of SEM and TEM were prepared respectively, then ultrastructure changes were observed. [ Result] The results showed that the method needed few samples, keep intact cell morphology and can see clear ultrastructure. [Conclusion] The method is suitable for ultrastructural observation of oocyte.

Synthesis and Characterization of GaN Nanorods by Ammoniating Ga_2O_3 /Co Films Deposited on Si(111) Substrates

GaN nanorods are successfully synthesized on Si（111） substrates with magnetron sputtering through ammoniating Ga2O3/Co films at 950℃. X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy,and Fourier-transform infrared spectroscopy are used to characterize the samples. The results demonstrate that the nanorods are single-crystal GaN with a hexagonal wurtzite structure and possess relatively smooth surfaces. The growth mechanism of GaN nanorods is also discussed.

Research on Pollen Grains of Tetraploid Lines and Diploid Control Line of Chrysanthemum cinerariifolium (Trev.) Vis.

[Objective] The aim was to study characters of pollen grains of tetraploid lines and diploid control line of Chrysanthemum cinerariifolium (Trev.) Vis.,morphological characters,fertility of pollen grain and germination percentage of seeds. [Method] Pollen grains were prepared by sulphuric acid-acetyl oxide decomposition method. The lengths of polar axis and equatorial axis of pollen grains were determined with general optical microscope. The morphology of pollen grains was observed with SEM (scanning electron microscope) and the typical visual fields of 2 500× (or 2 000×),7 000× were taken pictures. [Result] Comparing with the diploid control line,the pollen grains of five tetraploid lines which were tested were different from the diploid line in morphology,sculpture,etc.. 4 of the 5 tested samples were significant larger than the diploid line in size and one was similar to the diploid line. [Conclusion] This research provided references for breeding tetraploid improved varieties of Chrysanthemum cinerariifolium (Trev.) Vis. with good fertility and high germination percentage.

Descriptions of the Immature Stages of Three Species of the Tribe Ozophorini (Heteroptera:Lygaeidae:Rhyparochrominae) from China

Immature stages of 3 species of the tribe Ozophorini from China are described for the first time, they are Bryanellocoris orientalis Hidaka (3rd^5th instars), Primierus longispinus Zheng (4th^5th instars) and Vertomannus brevicollum Zheng (4th^5th instars). Abrief study on fine structure of pale spots on head, pronotum and abdomen of 5th instar nymph of Bryanellocoris orientalis Hidaka was also given.

Study on mechanical properties of composite materials by in-situ tensile test

The mechanical properties of the SiC fiber-reinforced Mg-Al metal matrix composite materials have been studied on internal microstructure by (scanning electron microscopy) SEM in-situ tensile test. The emergence and propagation of the crack, and the fracture behavior in materials have been observed and studied. It is found that in the case of the tensile test, the crack emerged in SiC fiber initially. In the case of the strong cohesion of the fiber-metal interface, the crack propagated in the fiber, meanwhile the fibers in the neighborhood of the cracked fiber began to crack and the Mg-Al metal deformed plastically, and at last the material fractured. Otherwise the toughness of the materials grows in the case of the lower cohesion of the fiber-metal matrix interface.

Colonization Pattern of Azospirillum brasilense Yu62 on Maize Roots

Plasmid pVK1001 which carried the gfp gene of GFPmut2, a mutant of GFP, was introduced into Azospirillum brasilense Yu62 by electroporation. Maize seedlings were inoculated with the GFP-labelled baeteria and grown gnotobiotically in flask with semi-solid agar medium. Observations were performed with confocal laser scanning microscopy (CLSM) and electron microscopy, respectively, at 8 d and 12 d after inoculation. Confocal laser scanning microscopy showed that A. brasilense Yu62 could penetrate into the cortex tissue, colonizing in the intercellular spaces of the parenchyma cells of the cortex tissue. Transmission and scanning electron microscopy (TEM) showed that the majority of the bacteria colonized on the root surface and only a minority of them resided in the root interior.

Obsevation for Epidermal Ultrastructure of Nostoc sphaeroides Kutzing under Scanning Electron Microscope

[Objective]The experiment aimed to explore a new way for observing surface structure of Nostoc sphaeroides Kutzing. [Method] The scanning electron microscope was used to observe the epidermal ultrastructure of wild and cultured Nostoc sphaeroides Kutzing. [ Result] The epidermis of wild and cultured Nostoc sphaeroides Kutzing showed mixture structure of fibril colloid which was reticular arranged. The difference between wild and cultured Nostoc sphaeroides Kutzing was that the outer epidermis of cultured Nostoc sphaeroides Kutzing had trichome distribution but the wild Nostoc sphaeroides Kutzing did not has such distribution. The obsevation results of under smaller than 10 μm by scanning electron microscope was touched thick and showed many folds and distortions. [ Conclusion] The scanning electron microscope was an effective way to study development of Nostoc sphaeroides Kutzing colony and it was worth popularizing.