Low Surface Brightness Galaxies Selected by Different Model Fitting

We present a study of low surface brightness galaxies(LSBGs) selected by fitting the images for all the galaxies inα.40 SDSS DR7 sample with two kinds of single-component models and two kinds of two-component models(disk+bulge):single exponential,single sersic,exponential+deVaucular(exp+deV),and exponential+sérsic(exp+ser).Under the criteria of the B band disk central surface brightness μ_(0,disk)(B)≥22.5 mag arcsec^(-2) and the axis ratio b/a> 0.3,we selected four none-edge-on LSBG samples from each of the models which contain 1105,1038,207,and 75 galaxies,respectively.There are 756 galaxies in common between LSBGs selected by exponential and sersic models,corresponding to 68.42% of LSBGs selected by the exponential model and 72.83% of LSBGs selected by the sersic model,the rest of the discrepancy is due to the difference in obtaining μ_(0) between the exponential and sersic models.Based on the fitting,in the range of 0.5≤n≤1.5,the relation of μ_(0) from two models can be written as μ_(0,sérsic)-μ_(0,exp)=-1.34(n-1).The LSBGs selected by disk+bulge models(LSBG_(2)comps) are more massive than LSBGs selected by single-component models(LSBG_1comp),and also show a larger disk component.Though the bulges in the majority of our LSBG_(2)comps are not prominent,more than 60% of our LSBG_(2)comps will not be selected if we adopt a single-component model only.We also identified 31 giant low surface brightness galaxies(gLSBGs) from LSBG_(2)comps.They are located at the same region in the color-magnitude diagram as other gLSBGs.After we compared different criteria of gLSBGs selection,we find that for gas-rich LSBGs,M_(*)> 10^(10)M_⊙ is the best to distinguish between gLSBGs and normal LSBGs with bulge.

Bulging Distortion of Austenitic Stainless Steel Sheet on the Partially Penetrated Side of Non-Penetration Lap Laser Welding Joint

Non-penetration laser welding of lap joints in austenitic stainless steel sheets is commonly preferred in fields where the surface quality is of utmost importance.However,the application of non-penetration welded austenitic stainless steel parts is limited owing to the micro bulging distortion that occurs on the back surface of the partial penetration side.In this paper,non-penetration lap laser welding experiments,were conducted on galvanized and SUS304 austenitic stainless steel plates using a fiber laser,to investigate the mechanism of bulging distortion.A comparative experiment of DC01 galvanized steel-Q235 carbon steel lap laser welding was carried out,and the deflection and distortion profile of partially penetrated side of the sheets were measured using a noncontact laser interferometer.In addition,the cold-rolled SUS304 was subjected to heat holding at different temperatures and water quenching after bending to characterize its microstructure under tensile and compressive stress.The results show that,during the heating stage of the thermal cycle of laser lap welding,the partial penetration side of the SUS304 steel sheet generates compressive stress,which extrudes the material in the heat-affected zone to the outside of the back of the SUS304 steel sheet,thereby forming a bulge.The findings of these experiments can be of great value for controlling the distortion of the partial penetrated side of austenitic stainless steel sheet during laser non-penetration lap welding.

Ballistic performance of spherical fragments penetrating PCrNi3MoV target plates

PCrNi3MoV steel is a medium-carbon,low-alloy quenched and tempered steel that finds its applications in military gun barrels due to the high wear resistance and ablation resistance.To study the penetration and failure modes of PCrNi3MoV plates impacted by tungsten spheres,tungsten spheres of various diameters(5 mm,8 mm,and 10 mm)were used to impact PCrNi3MoV steel plates with thicknesses of 6 mm,9 mm,and 14 mm.The penetration performance of the spheres was analyzed for different velocities,and the ultimate penetration velocity of the plate was obtained.It was found that the primary failure modes of the PCrNi3MoV plate were compression pitting failure and shear failure.Using the dimensional analysis method,a relationship between the bulge height of the steel plate and the fragment velocity,an equation for the ultimate penetration velocity,and a relationship between the target penetration energy and the fragment velocity were obtained.Then,a projectile-target action index was proposed to describe the process of tungsten spheres with different velocities impacting target plates.The results suggested that under the same thickness of the target plate,a larger-diameter fragment required more kinetic energy to obtain the same ultimate penetration effect as a smaller-diameter fragment.The equations obtained through dimensional analysis predicted values that agreed well with experimental values,indicating that these equations can be applied to engineering applications.

Recent progress in hair follicle stem cell markers and their regulatory roles

Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increasing number of biomarkers have been used to isolate,label,and trace HFSCs in recent years.Considering more detailed data from single-cell transcriptomics technology,we mainly focus on the important HFSC molecular markers and their regulatory roles in this review.

The Bar-Bulge Relation in Non-dwarf SB0 Galaxies in the Central Region of Coma Cluster

In this paper we explore the formation of bars and present the bulge and bar properties and their correlations for a sample of lenticular barred(SB0)and lenticular unbarred(S0)galaxies in the central region of the Coma Cluster using HST/ACS data.In our sample,we identified bar features using the luminosity profile decomposition software GALFIT.We classified the bulges based on Sérsic index and Kormendy relation.We found that the average mass of the bulge in SB0 galaxies is 1.48×10^(10)M☉whereas the average mass of the bulge in S0 galaxies is 4.3×10^(10)M☉.We observe that SB0 galaxies show lower bulge concentration,low mass and also smaller B/T values compared to S0 galaxies.Using the Kormendy relation,we found that among the lenticular barred galaxies,82%have classical bulges and 18%have pseudo bulges.These classical bulges have low masses compared to the classical bulges of unbarred galaxies.S0,galaxies with massive classical bulges do not host bars.We also found that for all SB0s the bulge effective radius is less than the bar effective radius.SB0 galaxies with classical bulges suggest that the bar may have formed by mergers.

Analysis of bulging process of aluminum alloy by overlapping sheet metal and its formability

The influences of strength coefficient K, work hardening exponent n and thickness t of the overlapping sheet on bulging process are analyzed based on hardening material model. Also, bulging experiments are carried out by taking the aluminum alloy LF21 as formed sheet metal, and selecting overlapping sheet with different thicknesses and material properties, by which accuracy of the above analysis result is verified in the aspects of geometric shape, thickness distribution and limit bulging height. The results show that higher strength coefficient K, larger work hardening exponent n and proper thickness of the overlapping sheet are helpful to improve the formability and forming uniformity of formed sheet metal.

无血清K-SFM培养条件下大鼠毛囊Bu lge细胞生物学特性的研究

目的研究无血清K-SFM培养条件下,大鼠毛囊Bu lge细胞的生物学特性。方法分离大鼠毛囊Bu lge细胞,分别置于无血清的K-SFM培养基(实验组)及有血清DMEM/F12培养基(对照组)的培养条件下培养。比较Bu lge细胞在两种培养体系中的生长增殖和K19的表达状况。结果无血清培养的Bu lge细胞在克隆形成率及K19的表达率均明显高于对照组(P<0.05)。结论体外培养和扩增大鼠毛囊Bu lge细胞,无血清的K-SFM培养基较有血清DMEM/F12培养基更有利于Bu lge细胞的扩增和表型的维持。

毛囊bulge细胞在角膜缘基质诱导下向角膜上皮细胞分化的初步研究

目的探讨体外培养的毛囊bulge细胞向角膜上皮细胞分化的可能性。方法体外分离培养毛囊bulge细胞,然后在transwell中与角膜缘基质细胞共培养诱导分化,观察毛囊bulge细胞的分化情况,免疫组化检测K12及K19表达的变化。结果体外培养的毛囊bulge细胞保持高增殖,低分化状态。经过2周左右的共培养,毛囊bulge细胞逐渐分化,部分细胞K12表达阳性。结论角膜缘基质细胞可以诱导毛囊bulge细胞向角膜上皮细胞分化。

PPARγ2表达促毛囊bulge细胞向皮脂腺定向分化的研究

目的探讨毛囊bulge细胞向皮脂腺细胞分化的机制。方法构建携带过氧化物酶体增殖体激活受体γ2(peroxisomeproliferatoractivationreceptorγ2,PPARγ2)基因的绿色荧光蛋白(GFAP)质粒,通过质脂体转染到体外分离培养毛囊bulge细胞中,以转染空质粒的毛囊bulge细胞为对照,观察细胞的分化情况,运用免疫细胞化学检测细胞PPARγ和上皮膜抗原(epithelialmembraneantigen,EMA)的表达,油红O染色观察细胞脂滴合成情况。结果荧光显微镜下观察到已转染质粒的细胞呈现绿色荧光,能稳定表达PPARγ2mRNA,该细胞分化3周左右,部分细胞胞浆内出现脂滴,PPARγ、EMA及油红O染色阳性,而对照组为阴性,细胞内未见脂滴。结论毛囊bulge细胞可以分化为皮脂腺细胞,PPARγ2基因在其中起着重要作用。

毛囊Bulge细胞培养与生物学特性的研究

目的 探讨体外培养毛囊Bulge细胞的生物学性质。方法 采用一步消化法 ,显微分割毛囊Bulge区进行原代培养 ,观察细胞的形态特征、生长状况以及表达特性。结果 原代培养的第 2天便可见细胞生长 ,并表现出很强的增殖潜能 ,其生长期可达两周以上 ;光镜下表现出原始细胞形态特征 ,培养早期细胞能强表达K19和 β1 integrin ,并随培养时间延长呈下降趋势 ;原位染色亦可见 ,K19阳性细胞集中表达于毛囊Bulge区。结论 体外培养的毛囊Bulge细胞在形态、生长状况和标志物表达上都表现出幼稚细胞的性质 。

Friction coefficient in rubber forming process of Ti-15-3 alloy

The forming limit diagram of Ti-15-3 alloy sheet was constituted at room temperature. The effects of different punch and rubber hardness on the limit principal strain distributions were investigated experimentally. Finite element analysis models of the samples with dimensions of 180 mm×180 mm were established to analyze the friction coefficients of different interfaces. Effects of various friction coefficients on the strain distributions were studied in detail. Finally, the friction coefficients in the cold forming were determined by contrasting the strain results between the experimental data and the simulated ones.

Theoretical prediction and experimental investigation on formability of tailor-welded blanks

Based on the elastoplastic mechanical properties of the weld and heat affected zone metals obtained by a nanoindentation test, a theoretical calculation model was established for the forming limit diagram（FLD） of tailor-welded blanks（TWBs） on the basis of plastic constitutive relations and Hosford yield criteria. Hemispherical punch bulging tests were performed to verify the FLD theoretical calculation results. The results demonstrated that not only the FLD theoretical calculation of base materials but also that of TWBs had a good agreement with their experiments. Besides, poorer formability of TWBs caused its FLD significantly lower than that of base materials. The theoretical calculation model offers a reliable approach to obtain the specific FLD of TWBs.

Formability determination of AZ31B tube for IHPF process at elevated temperature

Ring hoop tension test and tube bulging test were carried out at elevated temperatures up to 480 ℃to evaluate the formability of AZ31B extruded tube for internal high pressure forming （IHPF） process. The total elongation along hoop direction and the maximum expansion ratio （MER） of the tube were obtained. The fracture surface after bursting was also analyzed. The results show that the total elongation along hoop direction and the MER value have a similar changing tendency as the testing temperature increases, which is quite different from the total elongation along axial direction. Both the total elongation along hoop direction and the MER value increase to a peak value at about 160 ℃. After that, they begin to decrease quickly until a certain rebounding temperature is reached. From the rebounding temperature, they begin to increase rapidly again. Burnt structure appears on the fracture surface when tested at temperatures higher than 420 ℃. Therefore, the forming temperature of the tested tube should be lower than 420 ℃, even though bigger formability can be achieved at higher temperature.

Viscous warm pressure bulging process of AZ31B magnesium alloy with different ellipticity dies

Based on the bulging principle of different ellipticity dies, the methyl vinyl silicone rubber with excellent thermal stability and heat transfer performance was chosen as the viscous medium. The finite element analysis and experiments of viscous warm pressure bulging （VWPB） of AZ31B magnesium alloy were conducted to analyze the influence of different ellipticity dies on the formability of AZ31B magnesium alloy. At the same time, based on the grid strain rule, the forming limit diagram （FLD） of VWPB of AZ31B magnesium alloy was obtained through measuring the strain of bulging specimens. The results showed that at the temperature range of viscous medium thermal stability, the viscous medium can fit the geometry variation of sheet and generate non-uniform pressure field, and as the die ellipticity increases, the difference value of non-uniform pressure reduces. Meanwhile, according to the FLD, the relationship between part complexity and ultimate deformation was investigated.

毛囊Bulge细胞的分离培养及生物学特性研究

目的分离培养大鼠毛囊Bulge细胞并观察其生物学特性。方法运用显微分离法及酶消化法分离大鼠毛囊Bulge细胞并进行培养,观察其增殖能力及细胞形态等的改变;采用免疫组化方法,检测毛囊Bulge细胞K19、β1整合素的表达情况。结果本方法培养的大鼠毛囊Bulge细胞纯度高、活力好,具有高增殖、低分化特性,同时表达K19、β1整合素。结论成功地分离培养了毛囊Bulge细胞,并在体外长期保持其低分化特性,为进一步深入研究毛囊发育分化提供了实验基础。

Radio Luminosity,Black Hole Mass and Eddington Ratio for Quasars from the Sloan Digital Sky Survey

We investigate the MBH-σ＊ relation for radio-loud quasars with redshifl z 〈 0.83 in Data Release 3 of the Sloan Digital Sky Survey （SDSS）. The sample consists of 3772 quasars with better models of the H/4 and [O Ⅲ] lines and available radio luminosity, including 306 radio-loud quasars, 3466 radio-quiet quasars with measured radio luminosity or upper-limit of radio luminosity （181 radio-quiet quasars with measured radio luminosity）. The virial supermassive black hole mass （MBH） is calculated from the broad Hβline, and the host stellar velocity dispersion （σ＊） is traced by the core [O Ⅲ] gaseous velocity dispersion. The radio luminosity and radio loudness are derived from the FIRST catalog. Our results are as follows： （1） For radio-quiet quasars, we confirm that there is no obvious deviation from the MBH-σ＊ relation defined for inactive galaxies when the uncertainties in ~IBH and the luminosity bias are concerned. （2） We find that the radio-loud quasars deviate more from the MBH-σ＊ relation than do the radio-quiet quasars. This deviation is only partly due to a possible cosmological evolution of the MBH-σ＊ relation and the luminosity bias. （3） The radio luminosity is proportional to MBH1.28＋0.23-0.16（LBol/LEdd） ^1.29＋0.31-0.24 for radio-quiet quasars and to -MBH3.10＋0.60-0.70（LBol/LEdd）^4.18＋1.40-1.10 - for radio-loud quasars. The weaker dependence of the radio luminosity on the mass and the Eddington ratio for radio-loud quasars shows that other physical effects would account for their radio luminosities, such as the spin of the black hole.

体外培养条件下毛囊bulge细胞分泌的β神经生长因子的检测

目的定性定量地检测毛囊bu lge细胞体外培养条件下分泌的β-神经生长因子(-βnerve growth factor,β-NGF)及其与bu lge细胞生长状态的关系。方法首先使用显微操作技术剥离出原代组织,然后培养原代细胞,使用超薄切片和透射电镜技术来观察原代细胞超微结构,使用酶联免疫吸附(enzym e linked immunosorbent assay,ELISA)方法测定原代bu lge细胞分泌的β-NGF,利用免疫细胞化学(immunocytochem istry,ICC)方法检测原代细胞中β-NGF的表达。结果成功培养出原代bu lge细胞,ICC方法检测到原代培养的bu lge细胞质表达强阳性β-NGF。超薄切片和透射电镜技术能够显示出原代培养bu lge细胞的内部结构,即核质比大,细胞器较少。通过ELISA方法能够测定出原代细胞分泌的β-NGF与体外原代培养的bu lge细胞特性呈规律性变化。结论原代bu lge细胞分泌的β-NGF呈规律性表达,即生长高峰时期表达最为丰富,这与毛囊bu lge细胞的生长状态具有规律性变化有关,因此他们具有必然的联系。

DETERMINATION OF PRESSURIZING CURVE AND COMPUTER CONTROL OF THICKNESS THINNING FOR SUPERPLASTIC BULGING

This paper proposes the assumption that the flow with viscous friction is the stretch of part of the sheet that lies along the walls of a die during the process of superplastic bulging according to superplastic flow equation and geometrical model of bulging of a sheet into a long trapezoid groove or truncated cone, by introducing the friction-factor P which describes the friction effect on the process. Also, the paper proposes the method of controlling thickness nonuniformity and develops the equipment which for uniform thickness of bulging, is automatically controlled with a computerl it also analyzes the important innuence of lubrication on thickness distribution of bulging materials. By the assumption, the relationship between bulging pressure and time is obtained in bulging of a sheet into the groove and cone, and p-t curve of multi-mould-cavity complicated bulging is discussed based on the analysis of single-mould-cavity bulging characteristics.

微卫星标记BMS2508和Bulge5在河南淮山羊中的遗传多样性研究

用2个微卫星标记,通过PCR扩增,利用12%非变性聚丙烯酰胺凝胶电泳和银染显色等方法对河南淮山羊进行微卫星DNA遗传多态性进行研究。结果显示:在Bulge5基因座上检测出6个等位基因,其片段大小在105～140 bp之间,其多态信息含量(PIC)、有效等位基因数(Ne)、平均杂合度(He)分别为0.734 0、3.182 0、0.832 5;BMS2508位点有6个等位基因,其片段大小在100～150 bp之间,其多态信息含量、有效等位基因数、平均杂合度分别为0.843 0、3.706 0、0.844 6。说明BMS2508和Bulge5等2个微卫星位点在河南淮山羊上均为高度多态位点,利用微卫星DNA多态性预测山羊的生产性能是可行的,本研究为山羊的选育、保种和开发利用提供了理论依据。

Variation of physical properties across the green valley for local galaxies

We selected a sample of nearby galaxies from the Sloan Digital Sky Survey Data Release 7(SDSS DR7) to investigate the variation of physical properties from the blue cloud to green valley to red sequence.The sample is limited to a narrow range in the color-stellar mass diagram. After splitting green valley galaxies into two parts—a bluer green valley(green 1) and a redder one(green 2) and three stellar mass bins,we investigate the variation of physical properties across the green valley region. Our main results are as follows:(i) The percentages of pure bulge and bulge-dominated/elliptical galaxies increase gradually from blue cloud to red sequence while the percentages of pure disk and disk-dominated/spiral galaxies decrease gradually in all stellar mass bins and different environments.(ii) With the analysis of morphological and structural parameters(e.g., concentration(C) and the stellar mass surface density within the central 1 kpc(Σ1)), red galaxies show more luminous and compact cores than both green valley and blue galaxies, while blue galaxies show the opposite behavior in all stellar mass bins.(iii) A strong negative(positive) relationship between bulge-to-total light ratio(B/T) and specific star formation rate(sSFR)(D_(4000)) is found from blue to red galaxies. Our results indicate that the growth in bulge plays an important role when the galaxies change from the blue cloud, to the green valley and to the red sequence.