“显——隐”的经纬——高行健长篇小说文本结构研究

在小说这一文类范畴中,尤其是鸿篇巨制的长篇小说,其独特的文本结构方式往往形成一道靓丽的风景线,而高行健的长篇小说《灵山》和《一个人的圣经》,无疑是将小说的独特结构方式演绎出丰富审美意蕴的经典个例。本文探讨了高行健长篇小说的文本结构问题、高行健长篇小说中"显"在的结构设置上的重要特征——奇偶章节间的独立叙述人称交织接替、"中国套盒"(或"俄罗斯套娃");高行健长篇小说"显"在结构之后所"隐"潜的深度美学意味——大型的对话、重复(或反复)的美。通过"显—隐"的小说文本经纬的展现,形成泾渭分明的高行健长篇小说的文本结构问题的系统研究。

Microstructure and formation process of Ni-pool defect in WC-8Ni cemented carbides

The morphologies and formation process of Ni-pool defects in WC?8Ni cemented carbides were studied. The SEM images show that Ni-pool generally has two kinds of morphologies: “island” in isolation and “ring” around a new phase. In the obtained samples with “ring-like Ni-pool”, WC, Ni and Ni2W4C (η phase) phases were detected in XRD patterns. Combined with SEM, EDX and XRD results, it is found that the phase in the center of the “ring-like Ni-pool” is Ni2W4C (η phase) and the main chemical components of Ni-pool are Ni, W and C. In addition, the relationships among large size Ni (agglomerated) particles, volatile impurities, pores and carbon content vs forming process of the Ni-pool defects for WC?8Ni cemented carbides are also presented and discussed.

Fabrication and ablation property of carbon/carbon composites with novel SiC-ZrB_2 coating

A novel SiC?ZrB2 coating was prepared using a two-step technique by slurry-sintering and chemical vapor reaction on carbon/carbon (C/C) composites. The SiC?ZrB2 coating was composed of the scattered ZrB2 phase and the continuous SiC phase. It was observed that a good adhesion was built between the coating and the C/C composites. The SiC?ZrB2 coating samples exhibited a better ablation resistance in comparison with the uncoated C/C composites. The SiO2?ZrO2 barrier layer, the heat dissipation of the gaseous products and the pinning effect of ZrO2 all contributed to the good ablation resistance of the SiC?ZrB2 coated composites.

Roles of Zr and Y in cast microstructure of M951 nickel-based superalloy

The influence of Zr and Y on the cast microstructure of a nickel-based superalloy was investigated by optical microscopy （OM）,scanning electron microscopy（SEM）,electron probe micro-analysis（EPMA）and X-ray diffraction（XRD）.Theγ＋γ′eutectic volume in the superalloy rises notably with the increase of Zr or Y content.Meanwhile,the morphologies of primary MC carbides change from needle and platelet-like to blocky shape with increasing Zr and Y doped.The XRD results show that the primary MC carbide lattice constant increases with Zr and Y additions,and EPMA investigation shows that the platelet-like MC carbides contain primarily Nb and C,while those carbides in blocky shape have 39.2%Zr and 39.6%Nb in average,.These influences on the cast microstructure can be attributed to the atomic size effects of Zr and Y.

Structure and mechanical properties of thick Cr/Cr_2N/CrN multilayer coating deposited by multi-arc ion plating

A Cr/Cr2N/CrN multilayer coating with a thickness of 24.4 μm was deposited by multi-arc ion plating. The coating was systematically characterized by field emission scanning electron microscopy(FESEM), X-ray photoelectron spectrometry(XPS), energy dispersive spectroscopy(EDS), X-ray diffraction(XRD) and transmission electron microscopy(TEM). Hardness and adhesion were tested by nanoindentation and scratch tester, respectively. The friction properties were investigated by a reciprocating UMT-3MT ball-on-disk tribometer in air and seawater. The results showed that the multilayer coating consisted of three different layers, with Cr,Cr2N and CrN phases, respectively. Compared with CrN single layer coating, the adhesion of the multilayer coating was improved significantly, the hardness of the multilayer coating was(21±2) GPa. The corrosion resistance of the multilayer coating was also improved in artificial seawater. The friction coefficient of multilayer coating was lower than that of CrN single layer coating both in air and seawater.

Effects of substituting La with M(M=Sm, Nd, Pr) on electrochemical hydrogen storage characteristics of A_2B_7-type electrode alloys

The partial substitution of M （M=Sm, Nd, Pr） for La was performed in order to ameliorate the electrochemical hydrogen storage performance of RE–Mg–Ni-based A2B7-type electrode alloys. The La0.8–xMxMg0.2Ni3.35Al0.1Si0.05 （M=Sm, Nd, Pr;x=0-0.4） electrode alloys were fabricated by casting and annealing and their microstructures were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The major phases （La, Mg）2Ni7 with the hexagonal Ce2Ni7-type structure and LaNi5 with the hexagonal CaCu5-type structure make up the basic microstructure of the experimental alloys. The discharge capacities of the as-cast and annealed alloys all gain their maximum values with the M （M=Sm, Nd, Pr） content varying. The electrochemical cycle stability of the as-cast and annealed alloys clearly rises with the M （M=Sm, Nd, Pr） content growing. Furthermore, the electrochemical kinetics of the alloys, including the high rate discharge ability, charge transfer rate, limiting current density and hydrogen diffusion coefficient, all present a increase trend at first and then decrease with the rising of M （M=Sm, Nd, Pr） content.

BONDING INTERFACE AND WEAR BEHAVIOR OF CBN GRAINS BRAZED USING NANO-TiC POWDER MODIFIED FILLER

A new kind of composite fillers,composed of Ag-Cu-Ti alloy and nano-TiC powders,is utilized to braze cubic boron nitride （CBN） grains and tool substrate. The bonding system,including the interfacial microstructure and reactive products between CBN grains and filler layer,is observed by optical microscope and scanning electron microscope （SEM）. Resistant-to-wear experiments of the brazed grains are performed. Results show that the nano-TiC powders evenly distribute in the filler layer so that the resultants grow compactly and uniformly on the surface of CBN grain. This indicates that the chemical bond is established between CBN grains and nano-TiC modified filler. Accordingly,the bonding strength of the grains is ensured. The CBN grains are worn smoothly without grain pull-out.

Microstructure, mechanical and oxidation characteristics of detonation gun and HVOF sprayed MCrAlYX coatings

Microstructure, mechanical property and oxidation resistance of MCrAlYX coatings prepared by detonation gun (D-gun) and HVOF spraying were investigated. Lamellar microstructure and uniform microstructure formed in D-gun sprayed MCrAlYX coating and HVOF sprayed coating, respectively. Element redistribution and formation of new phase took place during the detonation process. Besides, the porosity of D-gun sprayed coating was much lower than that of HVOF sprayed coating. On the mechanical property, the micro-hardnesses of the two coatings were in the same level (~HV 910). However, D-gun sprayed MCrAlYX coating exhibited larger standard deviation of microhardness due to its lamellar microstructure, and exhibited better bend bonding strength owing to the existence of residual compressive stress between the layers and particles. Meanwhile, due to the much more compact microstructure, D-gun sprayed MCrAlYX coating showed superior oxidation resistance to the HVOF sprayed coating. The continuous dense protective layer can form earlier in D-gun sprayed coating and thus suppress further oxidation and control the oxide thickness at a relatively low level.

Effects of CO_2 Enrichment on Microstructure and Ultrastructure of Two Species of Freshwater Green Algae

order to investigate the morphological response of freshwater green algae to elevated CO2 concentration, Chlamydomonas reinhardtii Dang and Scenedesmus obliquus Kutz were cultured with enriched CO2, and their microstructure and ultrastructure were examined by microscopy and electron microscopy. The effect of CO2 enrichment to 186 mumol/L, was insignificant on the shape and size of C. reinhardtii, but significant in reducing the volume of S. obliquus. High-CO2 increased the amount of chloroplast. The pyrenoids occurred in low-CO2-grown cells but not in high-CO2-grown ones and more starch granules were observed in the former.

Observation and characterization of asphalt microstructure by atomic force microscopy

The microstructure of asphalt is investigated by atomic force microscopy （AFM）. In order to analyze the impacts of asphalt types on microstructures, two neat asphalts with different penetration grades （50# and 70#） and one styrene-butadiene-styrene （SBS） modified asphalt are chosen. The influence of short-term aging is also studied. Based on the knowledge of asphalt＇s microproperties, the relationship between microstructures and healing property is analyzed. The results indicate that the microstructures of three asphalts are quite different and the effects of aging on the surface characteristics for different asphalts are also different. It is proposed that the bee structure is a type of wax crystal and it has a close relationship with the ＂bridge-healing＂ mechanism. The findings may reveal the formation mechanism of microstructure and the healing property for asphalts.

Microstructure and mechanical properties of TiAl-based alloy prepared by double mechanical milling and spark plasma sintering

A fine-grained TiAl alloy with a composition of Ti-45Al-2Cr-2Nb-1B-0.5Ta-0.225Y （mole fraction, %） was prepared by double mechanical milling（DMM） and spark plasma sintering（SPS）. The relationship among sintering temperature, microstructure and mechanical properties was studied. The results show that the morphology of double mechanical milled powder is regular with size in the range of 20-40 μm and mainly composed of TiAl and Ti3Al phases. The main phase TiAl and few phases Ti3Al, Ti2Al and TiB2 were observed in the SPSed alloys. For samples sintered at 900 ℃ the equiaxed crystal grain microstructure is achieved with size in the range of 100-200 nm. With increasing the SPS temperature from 900 ℃to 1000 ℃ the size of equiaxed crystal grain obviously increases, the microhardness decreases from HV658 to HV616, and the bending strength decreases from 781 MPa to 652 MPa. In the meantime, the compression fracture strength also decreases from 2769 MPa to 2669 MPa, and the strain to fracture in compression increases from 11.69% to 17.76%. On the base of analysis of fractographies, it shows that the compression fracture transform of the SPSed alloys is intergranular rupture.

Welding of Ti-6Al-4V alloy using dynamically controlled plasma arc welding process

A novel dynamically controlled plasma arc welding process was introduced,which is able tominimize heat input into the workpiece materials while maintaining desired full penetration,and it was used to weld Ti-6Al-4V alloy sheets.The microstructures,facture surfaces and microhardness of the welded joints were characterized by using optical microscope,scanning electron microscope （SEM） and Vickers microhardness tester.Comparing with welds such as gas tungsten arc and conventional plasma arc processes,the experimental results revealed the improvements when using the present process including：1） reducing prior-beta （β） grain size and prohibiting formation of hard martensite phases in the fusion zone due to the decreased heat input;and 2） better toughness and higher hardness.

Microstructure of TA2/TA15 graded structural material by laser additive manufacturing process

TA2/TA15 graded structural material（GSM） was fabricated by the laser additive manufacturing（LAM） process. The chemical composition, microstructure and micro-hardness of the as-deposited GSM were investigated. The results show that the TA2 part of exhibiting near-equiaxed grains was Widmanst？tten α-laths microstructure. The TA15 part containing large columnar grains was fine basket-weave microstructure. The graded zone was divided into four deposited layers with 3000 μm in thickness. As the distance from the TA2 part increases, the alloy element contents and the β phase volume fraction increase, the α phase volume fraction decreases and the microstructure shows the evolution from Widmanst？tten α-laths to basket-weave α-laths gradually. The micro-hardness increases from the TA2 part to the TA15 part due to the solid solution strengthening and grain boundary strengthening.

Magnetostriction and structural characterization of Fe-Ga bulk alloy prepared by copper mold casting

Rapidly solidified Fe100-xGax （x=16-20） alloy rods were prepared by induction melting and copper mold casting under the protection of inert gases. The optical microscopy observation shows that the large and elongated columnar grains grow along the radial direction, which is parallel to the temperature gradient direction. The preferred orientation texture along the axial direction of the rod was detected by XRD. With the increase of Ga content, the saturation magnetization （Ms） of the alloys decreases distinctly and the dynamic response in low magnetic field increases drastically, the maximum longitudinal saturation magnetostriction for as-cast Fe82Ga18 alloy rods is 92×10-6 under an applied magnetic field strength of 30 kA/m. The large magnetostriction of Fe100-xGax alloys is attributed to the rapidly solidified disordered A2 phase and the high concentration of short range order of Ga atom clusters, which are arranged in the direction and finally trigger the formation of modified-DO3 structure, just as shown by the split of the （200） diffraction peak. Ordered DO3 phase is not conducive to the magnetostriction.

Microstructure Observation on the Follicular Development of Blue Fox during the Estrous Period

[Objective] The ovary microstructure and the changes of the follicle during the development period of blue fox during the estrous period were studied.[Method] Ten left ovaries were collected from 10 female blue foxes during the estrous period. The histological structure of the ovary and follicular development process were observed by using optical microscope. And 30 primordial follicles, 30 primary follicles, 15 growing follicles, 15 vesicular follicle, 15 mature follicles and the oocytes in the follicles of different developing stages were measured and photographed by eyepiece micrometer and photomicrographic technique respectively. [Result] The ovary of blue fox consisted of germinal epithelium, tunica albuginea, cortex and medulla. The cor- tex, which was located at the periphery of the ovary, contained many interstitial cells and follicles at different developing stages. Medulla was located below the cortex, with a lot of blood vessels. The diameters of follicles at different developmental stages and oocytes had greater differences during the developmental period of follicle. The diameter of follicles was 45.45-974.55 μm and the diameter of oocytes was 30.23-147.27 μm. The zona pellucida appeared at the primary follicle stage. The atresia of follicles occurred at all the developmental stages of follicle and the main manifestations were the shrunk oocyte and karyon, and loose and degraded granular cells. [Conclusion] The research provided histological basis for revealing the reproductive mechanism of female blue fox.

Microscopic Structure of Rabbit Hair

[Objective] The paper was to explore the microscopic structure of rabbit hair. [Method] Single rabbit hair with typical features was selected to observe its mi- croscopic structure from tip to root, and its fiber diameter was also measured. [Result] The rabbit hair tip was constituted by scale layer and cortical layer, without medullary layer; the middle part was generally constituted by scale layer, cortical layer and medullary layer; the root had no medullary layer, and the scale layer was wheatear-shaped. This was the property of rabbit hair, which could be used for comparative studies with other animal fiber and species identification. Rabbit hair had developed medullary layer, and fiber diameter was positively related to column number of medullary cavity. The hair generally was single column, and coarse hair was multi-column. Single rabbit hair was the finest in the tip, coarse in the middle and tapering in the root. The diameter difference of various parts was large, and the ex- ternal growth characteristics was spindle-shaped. [Conclusion] Using biological micro- scope method to identify different animal fur and product species is more objective and simple.

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The microstructure and properties of TZP ceramics fabricated from spray dried powder differing in granule morphology and deformability are determined.The effects of the feed slurry solids content on the granule character are discussed.The lower solid content results in hard and tough ‘donut’ shaped granules that resist deformation during compaction.The microphotograph shows that relatively large intergranular pores formed by incomplete deformation of granules persist during sintering and are the major strength limiting defects in fired material.Sintered material produced from uniform and deformable granules has a homogeneous microstructure and relatively high mean strength.

A Comparative Study on Microstructure between Isatis indigotica Fort.and Baphicacanthus cusia(Nees) Bremek.

[Objective] This study aimed to compare the microstructure between I. in- digotica Fort. and B. cusia （Nees） Bremek. [Method] Microstructure of I. indigotica Fort. and B. cusia （Nees） Bremek. with different sources were compared and analyzed by using digital microscopy. [Result] Comparison result of the microstructure shows that reticulate vessels, single starch granules, multiple starch granules and stone cells are mostly observed in I. indigotica Fort.; pitted vessels, parenchyma cells with small pits, single starch granules and cystolith are mostly observed in B. cusia （Nees） Bremek., which indicated that microstructure of L indigotica Fort. and B. cusia （Nees） Bremek. are significantly different. [Conclusion] Microstructure char- acteristics of I. indigotica Fort. and B. cusia （Nees） Bremek. established in this study can be used to evaluate the quality of these two kinds of Chinese herbal medicines, which also provide scientific basis and methods for comprehensively studying the quality standard of /. indigotica Fort. and B. cusia （Nees） Bremek. Key words Isatis indigotica Fort.; Baphicacanthus cusia （Nees） Bremek.; Microstruc- ture; Quality

MICROSTRUCTURE AND AMYLASE ACTIVITY OF CHINESE CABBAGE SEED DURING DRYING PROCESS

A seed is the carrier of life,and research on the heat and mass transfer of a seed has already stridden toward the level of microcosm,such as cell protoplasm,cell organism,and molecular membrane.By means of a transmission electron microscope,the authors of this paper observed the microstructure of cotyledon tissue slices of the Chinese cabbage seed with a moisture content of 13% (on dry basis) and that with a moisture content of 4.3% (on dry basis) for drying 2 h at 45 ℃.The compared result was that only wrinkles had been discovered on the cell walls of the seed dried for 2 h,without any significant change for other organelles.Study on the enzyme activity shows that after a germination for 48 h,the relative activity of α amylase of the Chinese cabbage seed dried for 2 h at 45 ℃,decreased by 5.8%,whereas that of the seed dried 2 h at a temperature of 67 ℃ decreased by 30.1%.This work shows that the drying factors have greatly influence on the seed microstructure,enzyme activity,which is directly positive to seed viability.Combined with the analysis of the critical safe drying temperature of the vegetable seed,it can be concluded that enzyme activity is also the function of the drying temperature,the moisture content and the drying time.

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.