Shear behavior of two-order morphology in rock joints

Two-order morphology of rock joints named as waviness and unevenness can be separated by morphology classification method,which plays a decisive role in the evolution of shear stress during the shear test.The joint morphology is obtained by using 3D printing and 3D laser scanning techniques and the joint model samples in two-order morphology are produced by cement mortar.Then,shear tests are performed under different normal loads.Results shows that the waviness is dominant in the total morphology during the shear test,and the shear contribution of unevenness mainly occurs in the climbing phase of shearing process.Comparing the failure modes of two-order morphology,waviness mainly embodies shear dilation characteristics and unevenness mainly shows shear wear characteristics.Based on this,a quantitative parameter is proposed to represent the ratio of the peak shear strength of the two-order morphology to that of total morphology.The functional relationship between the peak shear strength of total and two-order morphologies is determined,providing a theoretical method for further in-depth study on the shear strength of the interaction with two-order morphology of rock joints.

Effect of C/S Ratio on Morphology and Structure of Hydrothermally Synthesized Calcium Silicate Hydrate

The samples of the C-S-H series were synthesized by hydrothermal reaction of fumed silica, CaO and deionized water at initial C/S ratios between 1.0-1.7. Phase composition and structural and morphology characteristics of C-S-H samples were analyzed by XRD, IR and SEM. The experimental results showed that the d-spacing of （002）, （110） and （020） decreased, the d-spacing of （200） increased, and the d-spacing of （310） varied randomly, the polymerization of silica tetrahedra of C-S-H decreased, and morphology of C-S-H samples varied from sheet shapes to long reticular fibers as C/S ratio increased.

Effect of Polymer on Morphology and Structure of Calcium Silicate Hydrate Prepared via Precipitation Method

The effects of polyaerylamide （PAM） and polyvinyl alcohol （PVA） on morphology and structure of calcium silica~ hydrate with C/S 1.0-1.7 prepared via precipitation in solution were investigated by XRD, FT-IR and TEM techniques. The results show that incorporation of the polymers decreased the order degree, increased the interlayer spacing and disturbed the layered stacking of C-S-H. Interlayer spacing expansion depended on C/S ratios and type of polymer. Interlayer spacing expansion had a minimum at C/S 1.0 and a maximum at C/S 1.3 and 1.5. Interlayer spacing expansion of PAM was bigger than that of PVA with the same C/S. C-S-H added with PVA mainly exhibited foil-like and fibrillar morphology. The fibrils were of variable length from a few tens of nanometers to a few hundreds of nanometers. Fibrils or foils seemed to be longer in the presence of PVA.

纳米C-S-H的合成及其对普通硅酸盐水泥早期水化的影响

为提高水泥基材料的早期强度,制备了纳米C-S-H悬浮液,并通过XRD和Zeta电位对其组成和粒度分布、稳定性进行了分析。通过水化放热、热重分析和扫描电子显微镜扫描电镜(SEM)研究了纳米C-S-H对硅酸盐水泥早期强度发展、水化放热、水化产物的影响。结果表明:合成了具有半结晶结构的稳定的纳米C-S-H悬浮液。纳米C-S-H的加入促进了C3S的水化,尤其是在前24 h,并使水泥的水化诱导期明显缩短。含有0.05%纳米C-S-H砂浆的8 h、16 h和24 h抗压强度分别提高了176.0%、145.6%和43.9%,与此同时,砂浆的3 d抗压强度没有明显减少。

Neomicrocoleus gen.nov.(Microcoleaceae,Oscillatoriales),a novel cyanobacterial genus from benthic mats in a water channel

A new filamentous cyanobacterial strain(CHAB 4127)was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin,China.The polyphasic approach combining morphological,ultrastructural,ecological,and molecular features was used to characterize this studied strain.The strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy,and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like groups.The phylogenetic position of CHAB 4127 based on 16S rRNA gene sequences,is shown to be clearly clustered into an independent clade with the newly established genus Microcoleusiopsis.The maximum similarity of 16S r RNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%,and the ITS secondary structures is also obviously different from other members of Microcoleaceae.Based on all the above evidence,we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus,with its type species,Neomicrocoleus tianjinensis.

扭紧力矩对SWRM10K螺栓疲劳性能影响的研究

对扭紧力矩分别为0、12.5、22.0、29.5和35.0 Nm的SWRM10K钢螺栓进行轴向加载疲劳实验,获取螺栓的疲劳S-N数据。对比不同扭紧力矩下螺栓疲劳S-N特性,分析扭紧力矩对螺栓疲劳性能的影响。采用SEM观察螺栓试样的断口形貌,结合EDS分析裂纹萌生区元素分布,揭示螺栓疲劳断裂的规律。研究结果表明:增加扭紧力矩能有效提升该螺栓疲劳极限,但增加到一定程度提升效果明显下降,扭紧力矩值接近29.5 Nm较为合理。在该扭紧力矩下,螺栓疲劳极限为141 MPa,与未施加扭紧力矩相比提升了62.1%。螺栓疲劳断口分为3个区域:裂纹萌生区、扩展区和瞬间断裂区。在高应力幅下,裂纹萌生于试样表面,由晶体滑移引起;在低应力幅下,裂纹同样萌生于试样表面,但由晶体滑移或夹杂物引起。

N/S co-doped 3D carbon framework prepared by a facile morphology-controlled solid-state pyrolysis method for oxygen reduction reaction in both acidic and alkaline media

Developing high-performance non-precious metal electrocatalysts for oxygen reduction reaction(ORR)is crucial for the commercialization of fuel cells and metal-air batteries.However,doped carbon-based materials only show good ORR activity in alkaline medium,and become less effective in acidic environment.We believe that an appropriate combination of both ionic and electronic transport path,and well dopant distribution of doped carbon-based materials would help to realize high ORR performance un-der both acidic and alkaline cond让ions.Accordingly,a nitrogen and sulfur co-doped carbon framework with hierarchical through-hole structure is fabricated by morphology-controlled solid-state pyrolysis of poly(aniline-co-2-ami no thiophenol)foam.The uniform high concentrations of nitrogen and sulfur,high intrinsic conductivity,and integrated three dimensional ionic and electronic transfer passageways of the 3D porous structure lead to synergistic effects in catalyzing ORR.As a result,the limiting current density of the carbonized poly(aniline-co-2-aminothiophenol)foam is equivalent to commercial Pt/C in acidic environment,and twice the latter in alkaline medium.

Characteristics of corneal aberration in patients with bilateral keratoconus and unilateral corneal Vogt’s striae

AIM:To assess the corneal high-order aberration(HOA)and its correlation with corneal morphological parameters in patients with bilateral keratoconus(KCN)and unilateral Vogt’s striae.METHODS:A total of 168 eyes of 84 patients with KCN,whose corneas had definite signs of unilateral Vogt’s striae,were enrolled.Corneal HOA and morphological parameters were measured using Pentacam HR.RESULTS:The corneal morphological parameters between KCN eyes with and without Vogt’s striae were evidently different(P<0.001).The 3rd coma 90°,4th spherical aberration,5th coma 90°,root-mean-square(RMS)(total),and RMS(HOA)in the front,back surfaces and total cornea in KCN eyes with Vogt’s striae were significantly higher than those in KCN eyes without Vogt’s striae(P<0.001).In KCN eyes with Vogt’s striae,the 3rd coma 90°and 4th spherical aberration in the front surface and total cornea were negatively correlated with flat keratometry value(K1),steep keratometry value(K2),mean keratometry value(Km),maximum keratometry value(Kmax),anterior corneal elevation(ACE),and posterior corneal elevation(PCE;P<0.05).The 3rd coma 90°,4th spherical aberration in back surface and RMS(total),RMS(HOA)in the front,back surfaces,total cornea were positively correlated with K1,K2,Km,Kmax,ACE,and PCE(P<0.05).CONCLUSION:Corneal HOA especially vertical coma and spherical aberration may increase when Vogt’s striae appeared in KCN eyes.The scale of increase is significantly related with changes in corneal shapes.

MORPHOLOGY OF(Mn,Fe)S SINGLE CRYSTAL GROWTH IN CAST STEEL

The step pattern of single crystal growth and the morphology at equilibrium state of(Mn, Fe)S on the wall of micro-voids in ZG25 cast steel have been observed using scanning electron microscope.The face-centred cubic(Mn,Fe)S single crystal at equilibrium state is shown to be tetrakaidecahedron consisted of eight{111}planes and six{100}planes,and is a typical example of the O_h—m3m cubic crystal system.

喀西茄Solanum khasianum形态特征·分布与危害研究

对新入侵的外来杂草喀西茄Solanum khasianum的植株、花、果实、种子的形态特征、分布与危害开展了研究,并对同属的近似种(检疫性杂草北美刺龙葵Solanum carolinense L.、刺萼龙葵Solanum rostratum Dunal.、水茄Solanum torvum Swartz和外来杂草蒜芥茄Solanum sisymbriifolium Lam.)等形态特征进行比较,对快速准确鉴定茄属重要杂草、提高疫情检出率及加强对检疫重要杂草的风险管理提供信息依据。

Morphology, ultrastructure and phylogeny of Cyanothece sp. (Cyanobacteriaceae: Cyanophyceae) isolated from the eastern Indian Ocean

One strain of unicellular greenish algae embedded by mucilage was successfully isolated from equatorial area in the Indian Ocean. Microscopic observation, ultrastructure features and genetic identification confirmed that the strain was closely related to Cyanothece sp., which was a cyanobacteria species with great ecological significance. Cells were solitary with oval or bacilliform shapes. Diameters of this strain were relatively small, ranging from 2.5 to 6.5 μm on average. Ultrastructure of cells was simple. Thylakoids were arranged parietal and keritomized content were observed in the thylakoid region. Various electron-transparent granules with low electron-dense region as well as cyanophycin or glycogen granules-like organelle and carbonxysomes were also observed. For pigment composition, the dominant pigments were chlorophyll α, β-Carotene, Zeaxanthin and an unknown pigment, contributing 23.8%, 26.1%, 14.7% and 15.7% to total pigments respectively. The phylogenetic analysis of 16S rRNA gene and n/fH gene confirmed that Strain EIO409 was closely related with Cyanothece sp..

Bill Morphology Does Not Influence Vocal Performance in Darwin’s Small Tree Finch on Floreana Island

Bird song is used for mate attraction and is important for establishing reproductive isolation. Current research highlights performance constraints on song production that may be influenced by variation in bill morphology. Darwin＇s finches are a model system for studying the relationship between morphology and song performance, with previous studies suggesting that lower vocal performance is correlated with larger bill size. Here, we tested for a relationship between bill morphology and vocal performance in Darwin＇s Small Tree Finch （Camarhynchus parvulus） on Floreana Island. We found no evidence of a correlation between bill morphology and vocal performance. This finding is in agreement with prior study of the Small Tree Finch, but contrasts a greater body of work addressing song in Darwin＇s Finches. We discussed our findings in the context of ecological divergence, and ecological variation across species.

Species diversity of thrips (Thysanoptera) in selected avocado orchards from Mexico based on morphology and molecular data

Avocado is one of the most important crops in the world, and Mexico is the largest producer of this fruit. Several insect pests affect its production, and thrips are amongst the most important. A key step in the design of control methods is accurate species identification. Despite this, formal reports on species diversity of thrips in Mexico are very scarce. Morphological identification can sometimes be time-consuming and inconclusive. Therefore, we explored the species diversity of thrips in Mexican avocado orchards （Michoacan state） based on partial sequences of the mitochondrial gene cytochrome oxidase subunit I （COl）. Forty-four specimens were analysed, which represented approximately 8% of all individuals collected from five localities distributed in three Municipalities. All specimens were analysed using the COl marker, and specimens within the genera Frankliniella were also analysed using a marker within the D2 domain of the 28S （28SD2） nuclear ribosomal DNA. Molecular identifications were confirmed using morphological taxonomy. Overall, six genera were found （Neohydatothrips, Scirtothrips, Frankliniella, Arorathrips, Caliothrips and Leptothrips）. AII genera contained only one species, except Frankliniella, for which there were six species. Data from the two molecular markers suggest the existence of cryptic species within Mexican F. occidentalis populations.

A Morphology-Driven Method for Measuring Technology Complementarity:Empirical Study Involving Alzheimer’s Disease

Purpose:Measuring the exact technology complementarity between different institutions is necessary to obtain complementary technology resources for R&D cooperation.Design/methodology/approach:This study constructs a morphology-driven method for measuring technology complementarity,taking medical field as an example.First,we calculate semantic similarities between subjects(S and S)and action-objects(AO and AO)based on the Metathesaurus,forming clusters of S and AO based on a semantic similarity matrix.Second,we identify key technology issues and methods based on clusters of S and AO.Third,a technology morphology matrix of several dimensions is constructed using morphology analysis,and the matrix is filled with subjects-action-objects(SAO)structures according to corresponding key technology issues and methods for different institutions.Finally,the technology morphology matrix is used to measure the technology complementarity between different institutions based on SAO.Findings:The improved technology complementarity method based on SAO is more of a supplementary and refined framework for the traditional IPC method.Research limitations:In future studies we will reprocess and identify the SAO structures which were not in the technology morphology matrix,and find other methods to characterize key technical issues and methods.Furthermore,we will add the comparison between proposed method and traditional and mostly used complementarity measurement method based on industry chain and industry code.Practical implications:This study takes medical field as an example.The morphology-driven method for measuring technology complementarity can be migrated and applied for any given field.Originality/value:From the perspective of complementary technology resources,this study develops and tests a more accurate morphology-driven method for technology complementarity measurement.

Automatic detection of pulse morphology patterns &cardiac risks

Analysis of arterial pulse waveforms is important for non-invasive diagnosis of cardiovascular functions. Large samples of IPG signal records of radial arterial pulse show presence of eight different types of shapes (morphological patterns) in the pulse waveforms. In this paper we present an efficient computational method for automatic identification of these morphological patterns. Our algorithm uses likelihood ratio of cumulative periodogram of pulse signals and some geometrical criteria. The algorithm is presented with necessary details on signal processing aspects. Results for a large sample of pulse records of adult Indian subjects show high accuracy of our algorithm in detecting pulse-morphology patterns. Variation of pulse-morphology with respect to time is also analyzed using this algorithm. We have identified some characteristic features of pulse-morphology variation in patients of certain cardiac problems, hypertension, and diabetes. These are found relevant and significant in terms of physiological interpretation of the associated shapes of pulse waveforms. Importance of these findings is highlighted along with discussion on overall scope of our study in automatic analysis of heart rate variability and in other applications for non-invasive prognosis/diagnosis.

X52钢在含H_(2)S水溶液中的腐蚀规律研究

本试验采用高压反应釜对X52钢在不同条件下(温度、H_(2)S浓度、NaCl浓度、介质流速)的H_(2)S腐蚀行为进行了研究,并对试样腐蚀速率和表面腐蚀产物形貌进行评价分析。试验结果表明:(1)当温度低于60℃时,腐蚀速率随着温度升高而增大;温度高于60℃时,随着温度升高腐蚀速率减小,试样表面转化为保护性好、附着力强、致密的腐蚀产物膜;(2)H_(2)S浓度的增加对腐蚀速率无明显的影响;(3)腐蚀速率随着NaCl浓度升高而下降;(4)腐蚀速率随介质流速增大而增大。

Effects of Ca(Y)-Si modifier on interface morphology and solute segregation during directional solidification of an austenite medium Mn steel

The austenite medium Mn steel modified with controlled additions of Ca, Y, Si were directionally solidified using the vertical Bridgman method to study the effects of Ca（Y）-Si modifier on the solid-liquid （S-L） interface morphology and solute segregation. The interface morphology and the C and Mn segregation of the steel directionally solidified at 6.9 μtrn/s were investigated with an image analysis and a scanning electron microscope equipped with energy dispersive X-ray analysis. The 0.5wt% Ca-Si modified steel is solidified with a planar S-L interface. The interface of the 1.0wt% Ca-Si modified steel is similar to that of the 0.5wt% Ca-Si modified steel, but with larger nodes. The 1.5wt% Ca-Si modified steel displays a cellular growth parttern. The S-L interface morphology of the 0.5wt% Ca-Si＋1.0wt% Y-Si modified Mn steel appears as dendritic interface, and primary austenite dendrites reveal developed lateral branching at the quenched liquid. In the meantime, the independent austenite colonies are formed ahead of the S-L interface. A mechanism involving constitutional supercooling explains the S-L interface evolution. It depends mainly on the difference in the contents of Ca, Y, and Si ahead of the S-L interface. The segregation of C and Mn ahead of the S-L interface enhanced by the modifiers is observed.

高温扩散法制备B-S共掺杂单晶金刚石

利用高纯度的硼粉和硫粉,在1300℃的高温真空环境下,通过扩散装置制备出硼(B)、硫(S)共掺杂单晶金刚石。扫描电子显微镜、X射线能谱、拉曼光谱等测试结果表明,随着两种元素的掺入,金刚石的形貌和晶体质量发生变化。掺杂后的金刚石形貌复杂,蚀坑和沟壑内部形貌呈阶梯状,随着掺杂量的增加出现断层,并在蚀坑处检测出较高的硼原子和硫原子含量,掺杂B-S质量比为0.5的金刚石蚀坑处的硼原子和硫原子含量最高。随着杂质原子的渗入,拉曼半峰全宽值增大,金刚石的晶体质量下降。室温下进行霍尔检测结果表明,掺杂后的金刚石电阻率降低。B-S质量比为1和2的样品导电类型表现为p型;B-S质量比为0.5时,样品的霍尔系数为负值,导电类型为n型。

Morphological and genetic comparison of two strains of a Prorocentrum species isolated from Zhejiang coastal water of China and Masan Bay of Korea

In this paper, we examined the detailed morphology of two strains of Prorocentrum isolated from the coastal waters of Zhejiang (Wenling area), China, and Masan Bay of Korea. A taxonomic comparison was made among strains on the basis of morphological and molecular data. The cellular dimensions of the Chinese Wenling strain (LAMB090508) and Korean strain (PDKS0206) were similar and the cells of both strains were of asymmetric and elongated shape. The posterior end of most cells was rounded. Megacytic zones of aged cells were broader with dense tiny knobs. The roundish nucleus was located in the posterior part of the cell. A few irregular shaped chloroplasts were distributed within the cell. The nucleotide similarity of the two strains, determined from the 5.8S rDNA-ITS sequences, was 99.83%. The comparative results of morphology and molecular analysis suggest that both strains isolated from China and Korea were the identical species, Prorocentrum donghaiense Lu.

Foveal pit morphological changes in asymptomatic carriers of the G11778A mutation with Leber’s hereditary optic neuropathy

AIM:To investigate the foveal pit morphology changes in unaffected carriers and affected Leber’s hereditary optic neuropathy(LHON)patients with the G11778 A mutation from one family.METHODS:This study was a prospective cross-sectional study.Both eyes from 16 family members(age from 9 to 47 y)with the G11778 A mutation were analyzed and compared with 1 eye from 20 normal control subjects.Eleven family members with the G11778 A mutation but without optic neuropathy were classified as unaffected carriers(n=22 eyes).Five family members(n=10 eyes)expressed the LHON phenotype and were classified as affected patients.Retinal images of all the subjects were taken by optical coherence tomography(OCT),and an automatic algorithm was used to segment the retina to eight layers.Horizontal and vertical OCT images centered on the fovea were used to measure intra-retinal layer thicknesses and foveal morphometry.RESULTS:Thicker foveal thickness,thinner foveal pit depth,and flatter foveal slopes were observed in unaffected carriers and affected LHON patients(all P<0.001).Further,the slopes of all four sectors in the LHON were flatter than those in the unaffected carriers(all P<0.001).Compared with the control group,affected LHON patients had a thinner retinal nerve fiber layer(RNFL),ganglion cell layer and inner plexiform layer(GCL+IPL),and total retina(all P<0.01).The retinal nerve fiber layer(RNFL)of affected patients was 38.0%thinner than that of controls while the GCL+IPL was 40.1%thinner.CONCLUSION:The foveal pit morphology shows changes in both unaffected carriers and affects patients.RNFL and GCL+IPL are thinner in affected LHON patients but not in unaffected carriers.