Mitochondrial genomes of Tapes dorsatus and Cardita variegata:insights into Heteroconchia phylogeny

Heteroconchia,a widespread and abundant aquatic invertebrate,is an important clade of bivalve mollusks.The relationship between the three branches of Heteroconchia,Palaeoheterodonta,Archiheterodonta,and Euheterodonta has become a main controversy in molecular studies of the relationships between bivalves.In the present study,we assembled the complete mitochondrial genomes of Tapes dorsatus(Veneridae)and Cardita variegata(Carditidae)using high-throughput sequencing.C.variegata is the first mitochondrial genome belonging to the family Carditidae to be reported.We used 12 protein coding genes(excluding atp8)from the complete mitochondrial genomes of 146 species to recover the internal relationships of Heteroconchia.Our results support the traditional view of early branching of Palaeoheterodonta and the recovery of the monophyly of Palaeoheterodonta,Anomalodesmata,Imparidentia.Rearrangement analysis show that gene arrangement within Venerida was highly variable.Time-calibrated phylogenetic studies based on a relaxed molecular clock model suggested that Veneridae originated approximately 337.62 million years ago(Ma)and split into two major clades,whereas Carditidae originated approximately 510.09 Ma.Our results provide evidence of the internal relationships of Heteroconchia.

TAPES模式在普外科护生带教中的应用

目的:探讨TAPES模式在普外科护生带教中的应用效果。方法:采用便利抽样法选择2016年1月1日~2019年12月31日92名普外科实习护生,随机分为观察组和对照组各46名,对照组采用常规带教模式,观察组采用TAPES模式带教。比较两组护生出科理论和操作考核成绩、不良事件发生情况、护生带教满意度、参加普外科护理相关读书报告和操作比赛获奖人数。结果:观察组出科理论和操作成绩高于对照组(P<0.05);观察组自主学习能力优于对照组(P<0.05),观察组护生对临床带教老师的满意度高于对照组(P<0.05);观察组无护理不良事件发生,观察组参加普外科护理相关读书报告和操作比赛获奖人数多于对照组。结论:TAPES模式带教应用于临床护生的入科评估、教学活动的落实和评价反馈等各个环节,有利于明确教学目标,加强师生互动,提高教学质量,保证患者安全。

TAPES模式降低神经源性膀胱患者尿路感染率的效果研究

目的探索应用TAPES模式对降低脊髓损伤后神经源性膀胱患者尿路感染率的效果。方法选取2014年3月-2015年2月收治的96例神经源性膀胱行间歇导尿的患者作为对照组,采取医生管理,护士督导的模式进行管理;将2015年3-12月收治的112例神经源性膀胱行间歇导尿的患者为观察组,采用TAPES模式,即团队合作(T)、综合评估(A)、简化流程(P)、健康宣教(E)和目标监测(S)进行干预。观察比较两组患者的尿路感染率。结果对照组尿路感染率为58.33%,观察组尿路感染率降为23.21%,差异有统计学意义(P<0.05)。结论应用TAPES模式对预防和控制神经源性膀胱患者尿路感染的发生具有良好的效果,可广泛应用于临床护理。

从《étapes》看当代平面设计之趋势

从期刊设计和期刊内容2个方面分析了法国设计类高端刊物《étapes》,运用比较研究的方法对封面、刊头、内页版式、页码、印刷等部分进行探析,阐述了其在装帧设计上的特色和演变过程。在此基础上,将十余年《étapes》中刊登的内容作为研究素材,运用分析归纳的研究方法,对其关注的热点进行综述,提出了当代平面设计的五大主流趋势,研究结果可为当代平面设计创意思路提供参考。

Microstructure and properties of Bi-2223/Ag/Ni tapes

To reduce the production cost of Bi-2223 superconducting tapes, Bi-2223/Ag/Ni tapes were fabricated by the powder-in-tube process. The effect of heat treatment on the microstructure and critical current of the Bi-2223/Ag/Ni tapes were studied. The phase compositions of the samples were characterized using XRD. The microstructure was observed using SEM. Experimental results indicate that higher temperature is more conducive to the formation of Bi-2223 phase at an atmosphere of 8.5% O 2 . After the two-step heat treatment, the critical current of samples is about 67.5 A.

Slow Vortex Creep Induced by Strong Grain Boundary Pinning in Advanced Ba122 Superconducting Tapes

We report the temperature, magnetic field and time dependences of magnetization in advanced Ba122 superconducting tapes. The sample exhibits peculiar vortex creep behavior. Below 10 K, the normalized magnetization relaxation rate S = d ln(-M)/d ln(t) shows a temperature-insensitive plateau with a value comparable to that of low-temperature superconductors, which can be explained within the framework of collective creep theory. It then enters into a second collective creep regime when the temperature increases. Interestingly, the relaxation rate below 20 K tends to reach saturation with increasing the field. However, it changes to a power law dependence on the field at a higher temperature. A vortex phase diagram composed of the collective and the plastic creep regions is shown. Benefiting from the strong grain boundary pinning, the advanced Bal22 superconducting tape has potential to be applied not only in liquid helium but also in liquid hydrogen or at temperatures accessible with cryocoolers.

Thermal performance assessment of self-rotating twisted tapes and Al_(2)O_(3) nanoparticle in a circular pipe

In view of the practical importance of the heat transfer devices in various thermal engineering fields including chemical and nuclear engineering,this study aims at developing an effective method of heat transfer enhancement by using selfrotating twisted tapes(SRTTs)and Al_(2)O_(3) nanoparticles.The effect of the selfrotating twisted tapes and Al2O3 nanoparticles on the thermal performance was comprehensively investigated in a circular pipe.The experimental results indicated the heat transfer rate was effectively improved by SRTTs in comparison of plain tube.In addition,the heat transfer multiplier with SRTTs decreased from 1.38 to 1.08 with the Reynolds number increasing from 19,322 to 64,407,while the friction factor multiplier decreased from 1.61 to 1.32.Besides,the results indicated that the employment of Al_(2)O_(3) nanoparticles and SRTTs demonstrated superior thermal performance to the single SRTTs.As Reynolds number increases from 19,322 to 64,407,the heat transfer multiplier decreased from 2.08 to 1.18 in the mass concentration of 3.0%and from 1.38 to 1.08 in mass concentration of 0.0%.Finally,the new heat transfer and friction factor correlations considering the combined effect of Al2O3 nanoparticle and SRTTs were developed within 10%deviation of experimental values.

Investigation for Natural Convection Heat Transfer of Sucrose Solution Using a Converging and Diverging Tube with Regularly——spaced Twisted Tapes

The natural convection heat transfer of a 60% sucrose solution in a vertical converging-diverging tube(CD) with regularly-spaced twisted tapes(RSTT) has been investigated numerically and experimentally. The effects of wall temperature and number of RSTT on the Nusselt number were studied in detail. The distributions of velocity and temperature in the 60% sucrose solution were studied and the simulated results of CD with RSTT were compared with those of the smooth tube. The influence of Rayleigh number and RSTT on the Nusselt number was conducted experimentally. The results indicate that the Nusselt number of the 60% sucrose solution obviously increased with the number of RSTT but increased inconspicuously with 2 and more twisted tapes. The simulation shows that the distance for achieving an optimal heat transfer performance is 46 times the diameter of the tube. The mechanism of the natural convection heat transfer enhancement of the 60% sucrose solution in relationship with the CD and the RSTT was analyzed, and the change of average tangential velocity with the axial distance was presented to demonstrate that the enhancement of heat transfer was realized mainly because of the increase in tangential velocity.

Influence of Precursor Powder Fabrication Methods on the Superconducting Properties of Bi-2223 Tapes

Bi-2223 precursor powders are prepared by both oxalate co-precipitation(CP) and spray pyrolysis(SP) methods.The influence of fabrication methods on the superconducting properties of Bi-2223 tapes are systematically studied. Compared to the CP method, SP powder exhibits spherical particle before calcination and smaller particle size after calcinations with more uniform chemical composition, which leads to a lower reaction temperature during calcination process for Bi-2223 tapes. Meanwhile, the non-superconducting phases in SP powder are more uniformly distributed with smaller particle sizes. These features result in finer homogeneity of critical current in large-length of Bi-2223 tape, higher density of filaments and better texture after heat treatment. Therefore,the SP method could be considered as a better route to prepare precursor powder for large-length Bi-2223 tape fabrication.

Properties and Microstructuresof Three Kinds of Silversheathed Bi-2223 Tapes

Three kinds of silver-sheathed Bi(2223) oxide superconductor tapes (single-core tape, Ag-powder-added tape and multifilamentary type) were successfully prepared, namely, through the powder-in-tube method. The critical current density (Jc), the Jc-B characteristics, microstructures and the relation between Jc and strain of three kinds of tapes were evaluated and compared. The maximum Jc of three kinds of tapes at 77.7 K in zero magnetic field are 28700 A/cm2 for single-core tape, 20800 A/cm2 for Ag-powder-added tape, 11700 A/cm2 for multifilamentary tape. Single-core tapes exhibit high Jc values and good Jc-B characteristics.

J_c-B Characteristics and Microstructure Dependence of J_c of High J_c Bi-based Superconducting Oxide Tapes

Bi-based 2223 superconducting tapes with high critical current densities were prepared by silver-sheathing method. The relationship between processing, microstructure and property was discussed. The results of critical current density measurement at 77.7K with different applied magnetic field are as follows: Jc=2.87×104A/cm2 (OT) and Jc=4100A/cm2. Jc and Jc-B characteristics were obviously improved with temperature decreasing form 77K to 4.2K. Microstructure observations indicate that intermediate pressing with subsequent heat-treating can lower the porosity of superconductor inside the silver sheath. and reduce the amount and size of non-superconducting phases, leading to the formation of a strong c-axis-oriented texture and the emergence of high dislocation density within the 2223 grains, and consequently the Jc and Jc-B characteristics were improved.

HOT PRESSING AND ITS DEFORMATION MECHANISM OF Ag-SHEATHED DPSCCO SUPERCONDUCTING TAPES

ＨＯＴＰＲＥＳＳＩＮＧＡＮＤＩＴＳＤＥＦＯＲＭＡＴＩＯＮＭＥＣＨＡＮＩＳＭＯＦＡｇＳＨＥＡＴＨＥＤＤＰＳＣＣＯＳＵＰＥＲＣＯＮＤＵＣＴＩＮＧＴＡＰＥＳ①ＭａＹａｎｗｅｉ，ＷａｎｇＸｉａｎｊｉｎａｎｄＷａｎｇＺｕｔａｎｇＤｅｐａｒｔｍｅｎｔｏｆＭｅ...

Fabrication of Grain-oriented (Bi,Pb)_2Sr_2Ca_2Cu_3O_x Superconducting Tapes Using Magnetic Field and Vibration Technique

Highly textured (Bi,Pb)2Sr2Ca2Cu3Ox superconducting tapes have been fabricated by means of magnetic-field and vibration technique. This method is an effective way of improving the degree of grain alignment and density of oxide core in tapes after heat treatment and pressing cycles.Jc of above 20% was increased than that without treatment.

Optimization of Rolling Process for Bi(2223)/Ag Superconducting Tapes by a Statistical Method

Ag-sheathed (Bi,Pb)(2)SoCa(2)Cu(3)O(x) tapes were prepared by the powder-in-tube method. The influences of rolling parameters on superconducting characteristics of Bi(2223)/Ag tapes were analyzed qualitatively with a statistical method. The results demonstrate that roll diameter and reduction per pass significantly influence the properties of Bi(2223)/Ag superconducting tapes while roll speed does less and working friction the least. An optimized rolling process was therefore achieved according to the above results.

TEM Analysis on YBCO Composited Superconducting Tapes

The microstructures of the YBCO composited superconducting tapes with different J_c were analysed by TEM.The relationship between microstructure and J_c of the tapes is discussed in detail.It is demonstrated that J_c value of the tapes increases significantly with the decrease in the width of grain boundary,increase of the twin density and the reducing of the amount of precipitates at grain boundary.At grain boundary of the tapes,howev- er,small amount of non-superconducting phases can-not be avoided.For the fabrication of high J_c YBCO com- posited tapes,it is very important to improve the microstructure of the superconductor perfectly.

Deuton-M Magnetic Tapes and Sheets for Cards

Magnetic stripe is one of the major applications of magnetic materials. As a key component of the present card technologies magnetic stripes play reliable components for electronic data interchange in worldwide electronic payment systems such as financial cards, transit tickets and phone cards, etc. Magnetic stripes are available in various coercivity materials, widths, lengths, structures and colors with each types of transferable, lamination and pressure sensitive magnetic tapes of Deuton-M. Manufacturing process, structure and characteristics of Deuton-M magnetic tape and sheet are described.

Effects of Deformation and Heat－treatment Process on Texture of Bi－2223／Ag Su perconducting Tapes

The effects of deformation and heat-treatment on texture of BSCCO-2223/Ag tapes were investigatedby using single orientation quantitative texture analytical methods. The results show that when tapes weresintered at 835℃ for 24～48 h, the texture developed quickly, and further prolonging sintering tirne hadno significant influence on it. With the increase of deformation rate, the volume fraction of c-axis texturewas improved in linear form at first and then changed slowly. The highest volume fraction of c-axis texture(vol%)in these experiments is 33 . 49 % .

Improvement of Surface Morphology of Yttrium-Stabilized Zirconia Films Deposited by Pulsed Laser Deposition on Rolling Assisted Biaxially Textured Substrate Tapes

The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we focus on the influence of pulsed laser frequency and target crystalline type on surface morphology of YSZ films deposited by pulsed laser deposition （PLD） on rolling assisted biaxially textured substrate tapes. Usually two kinds of particles are observed in the YSZ layer： randomly distributed ones on the whole film and self-assembled ones along grain boundaries. SEM images are used to prove that particles can be partly removed when choosing dense targets of single crystalline. Lower frequency of pulsed laser also contributes to a smoother film surface. TEM images are used to view the crystalline structure of thin film. Thus we can obtain a basic understanding of how to prepare a particle-free YSZ buffer layer for YBCO in optimized conditions using PLD. The YBCO layer with nice structure and critical current density of around 5 MA/cm2 can be reached on smooth YSZ samples.

Thermohydraulics of Turbulent Flow Through Heat Exchanger Tubes Fitted with Circular-rings and Twisted Tapes

The influences of circular-ring turbulators （CRT） and twisted tape （TT） swirl generators on the heat transfer enhancement, pressure drop and thermal performance factor characteristics in a round tube are reported. The circular-ring turbulators were individually employed and together with the twisted tape swirl generators in the heated section of the tube. Three different pitch ratios （I/D = 1.0, 1.5, and 2.0） of the CRT and three different twist ratios （y/W= 3, 4, and 5） of the TT were introduced. The experiments were conducted using air as the working fluid under a uniform wall heat flux condition, for the Reynolds number between 6000 and 20000. The experimental results reveal that the heat transfer rate, friction factor and thermal performance factor of the combined CRT and qT are considerably higher than those of CRT alone. For the range examined, the Sncreases of mean Nusselt number, friction factor and thermal performance, in the tube equipped with combined devices, respectively, are 25.8%, 82.8% and 6.3% over those in the tube with the CRT alone. The highest thermal performance factor of 1.42 is found for the combined device consisting of the CRT with l/D = 1.0 and TT with y/W= 3. The correlations of the Nusselt number, friction factor and thermal performance factor of the tubes with combined devices are also developed in terms of Reynolds number, Prandtl number, twist ratio and pitch ratio.

3D Numerical Study on Compound Heat Transfer Enhancement of Converging-diverging Tubes Equipped with Twin Twisted Tapes

The paper presents a 3D numerical simulation of turbulent heat transfer and flow characteristics in converging-diverging tubes （CDs） and converging-diverg）ng tubes.equi.pped with twin counter-swirling twisted tapes （CDTs）. The effects of Reynolds number （Re= 10000-20000）, pitch length （P= 11.25, 22.5 mm）, rib height （e = 0.5, 0.8, 1.1 ram）, pitch ratio （8= 1 ＂ 8, 5 ＂ 4, 8 ＂ 1）, gap distance between twin t）visted tapes （b = 0.5, 4.5, 8.5 mm） and tape number （n = 2, 3, 4, 5, 6） on Nusselt number （Nu）, Iriction tactor 0＇） and thermal enhancement factor （r/） are investigated under uniform heat flux conditions,using water as working fluid. In order to illustrate the heat transter and tlu^d tlow mechamsms, flow structures m ~StJs and ~SDIs are presented. The obtained results reveal that all geometric parameters have important effects on the thermal performance of CD and CDT, and both CD and CDT show better thermal performance than plain tube at the constant pumping power. It is also found that the increases in the Nusselt number and friction factor for CDT are, respectively, up to 6.3%-35.7% and 1.75-5.3 times of thecorresponding bare CD. All CDTs have good thermal perbrmance with greater than 1 which indicates that the compound heat transfer technique of CDT is commendable for the maximum enhanced heat transfer rate.