THE ANISOTROPY OF FLUX DYNAMICS FOR YBa_2Cu_3O_7

ＴＨＥＡＮＩＳＯＴＲＯＰＹＯＦＦＬＵＸＤＹＮＡＭＩＣＳＦＯＲＹＢａ２Ｃｕ３Ｏ７ＤｉｎｇＳｈｉｙｉｎｇＲｅｎＣｏｎｇＹｉＨｕａｊｕｎ（ＤｅｐａｒｔｍｅｎｔｏｆＰｈｙｓｉｃｓ，ＮａｔｉｏｎａｌＬａｂｏｒａｔｏｒｙｏｆＳｏｌｉｄＳｔａｔｅＭｉｃｒｏｓｔｒ...     

THE CURRENT DENSITY DEPENDENCE OF ACTIVATION ENERGY IN HIGH－Tc SUPERCONDUCTOR HgBa_2Ca_2Cu_3O_（8＋x） IN LOW CURRENT DENSITY

ＴＨＥＣＵＲＲＥＮＴＤＥＮＳＩＴＹＤＥＰＥＮＤＥＮＣＥＯＦＡＣＴＩＶＡＴＩＯＮＥＮＥＲＧＹＩＮＨＩＧＨ－ＴｃＳＵＰＥＲＣＯＮＤＵＣＴＯＲＨｇＢａ_２Ｃａ_２Ｃｕ_３Ｏ_（８＋ｘ）ＩＮＬＯＷＣＵＲＲＥＮＴＤＥＮＳＩＴＹＴＨＥＣＵＲＲＥＮＴＤＥＮＳＩＴＹＤＥ...     

Bi_(2-x)Pr_xSr_2Ca_2Cu_3O_y超导体的研究

本文报导在零电阻温度为83K的Bi-Sr-Ca-Cu-O超导体中以不同含量Pr替代Bi的样品制备工艺、超导性能测试、X射线衍射及电镜的测量。测试表明Bi_(2-x)z Pr_x Sr_2 Ca_2 Cu_3 O_y中的Pr的摩尔含量x<0.2时样品的T_c在77K以上。这些样品随Pr含量的增加晶胞常数b,c有所增大,而a略有减小趋势。     

Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_y超导体的DSC研究

新型高T_c氧化物超导体Bi—Sr—Ca—Cu—O系,在100K以上呈现超导性,存在高T_c(～110K)相和低T_c(～80K)相,其零电阻转变温度(T_(c0))总是低于85K.适当掺Pb可以增强高T_c相,抑制低T_c相,降低烧结温度,提高零电阻转变温度.用固相反应法制得组分为Bi_(1.6)Pb_(0.4)Sr_2Ca_2Cu_3O_y的超导体,零电阻温度为107K,稳定性较好。现以此样品作示差扫描量热(DSC)分析,并配合XRD分析,试图了解该体系的结构相变及其与超导电性的关系.     

射频溅射法研制YBa_2Cu_3O_y高T_c超导薄膜

本文采用射频溅射法研制YBa_2Cu_3O_7高T_c超导薄膜,研究了溅射电压、气流、气压、基片及热处理工艺对超导膜成分、相结构及超导性能的影响,所得到的超导薄膜T_c(R=0)=89K,临界电流密度10~4～10~5A·cm~(-2).     

(CuTe)O_3对YBa_2Cu_3O_y织构生长的影响

用熔融织构法生长YBa_2 Cu_3(CuTe)xOy 系列,实验结果表明,生长过程中(CuTe)O_3 的参与有助于YBa_2 Cu_3 Oy 织构的形成,Te 可能具有俘获O 的能力.     

Tl_2Bg_2Ca_2Cu_3O_x单相超导块材的制备

本文研究了Ｔｌ＿２Ｂａ＿２Ｃａ＿２Ｃｕ＿３Ｏ＿ｘ（简称２２２３）单相超导块材的制备工艺。Ｘ射线衍射谱的分析和交流磁化率测量结果表明，对于名义组分为Ｔｌ＿２Ｂａ＿２Ｃａ＿２Ｃｕ＿３Ｏ＿ｘ的配料，在相当宽的温度范围（８７５℃～９５０℃）内烧结都有２２２３相生成。在８９７℃烧结２ｈ得到了纯的２２２３单相样品，其Ｔｃ（Ｒ＝０）值达１２０Ｋ。     

Sm_(1+x)Ba_(2-x)Cu_3O_y固溶体

用X射线衍射及氧含量分析法测定了Sm_(1+x)Ba_(2-x)Cu_3O_y固溶区域为0≤x≤0.4。当x<0.25时,Sm_(1+x)Ba_(2-x)Cu_3O_y属正交晶系;x=0.25时,发生从正交到四方的相变;在整个固溶区域内,T_c随x的增加而下降,直至淬灭。同时探讨了Sm_(1+x)Ba_(2-x)Cu_3O_y化合物在不同的淬火温度、氧含量与晶体结构、超导电性的关系。     

THE POTENTIALITY OF ENERGY-SAVING IN SHUTTLE LOOMS

In this paper,the effects of loom speed fluctuation on the mean speed and on the power ofdriving motor were investigated and the expressions for these effects were derived.Based on theenergy relationships,a new index of equivalent fluctuation was introduced,the connection be-tween this equivalent fluctuation and the energy of speed function on frequency domain was thenfound.In addition to the above theme,the residual kinetic energy of the shuttle and pickingmechanism,taken as a considerable part in the potentiality of loom energy-saving was also ana-lysed.According to the results of theoretical analyses,the ways of energy-saving in looms weresuggested.Finally,taking the loom of 1511 type as a practical example,the potentiality ofenergy-saving was calculated.     

TECTONIC DEVELOPMENT OF THE METAMORPHIC CORE COMPLEX OF THE WUGONGSHAN IN THE NORTHERN JIANGXI PROVINCE

ＴＥＣＴＯＮＩＣＤＥＶＥＬＯＰＭＥＮＴＯＦＴＨＥＭＥＴＡＭＯＲＰＨＩＣＣＯＲＥＣＯＭＰＬＥＸＯＦＴＨＥＷＵＧＯＮＧＳＨＡＮＩＮＴＨＥＮＯＲＴＨＥＲＮＪＩＡＮＧＸＩＰＲＯＶＩＮＣＥＳｕｎＹａｎ１）ＳｈｕＬｉａｎｇｓｈｕ１）Ｍ．Ｆａｕｒｅ２）Ｊ．Ｃｈａ...     

THE POLYELECTROLYTIC BEHAVIOURS OF ACIDIC AQUEOUS SOLUTIONS OF CHITOSAN IN THE PRESENCE OF EXTERNAL SALTS

The viscosities of chitosan-HAC in aqueous solution with various amount of NaAC have beenmeasured.Based on the analysis of experimental data,an empirical equation is deduced to des-cribe the relationship between the intrinsic viscosity and the concentration of external salt in thechitosan solution:[η]=[η]_∞+P/m~nand another empirical equation is proposed for describing the variation of reduced viscosity ofchitosan solution as function of salt and chitosan concentrations:(η_(sp)/c)_(salt)={D+A/(1+BC+HC~2)}·{1-1/(([η]_m=0)/([η]_(m=0)-[η]_∞)+P/m~R)+(C~/m~)}where the first term represents the relationship between viscosity and polymer concentration in theabsence of external salt,while the second term represents the correction value on viscosity in thepresence of external salt.     

THE GAUSS MAP OF SURFACES IN R~N

Let M be an oriented surface and G(2,k) be the Grassmannian.Smooth maps t1 M→G2（2，k) are studied to determine whether or not they are Gauss maps.Some new results have been obtained and some known results reproved.     

DISSIPATION OF THE FLOOD SERIES IN THE HUAIHE RIVER BASIN

Ｗｉｔｈｉｎｔｈｅｆｉｅｌｄｏｆｎｏｎｌｉｎｅａｒｐｈｅｎｏｍｅｎｏｎｒｅｓｅａｒｃｈ，ｓｅｖｅｒａｌｍｅｔｈｏｄｓｆｏｒｔｈｅａｎａｌｙｓｉｓｏｆｃｏｍｐｌｅｘｄｙｎａｍｉｃａｌｓｙｓｔｅｍｈａｖｅｒｅｃｅｎｔｌｙｂｅｅｎｐｒｏｐｏｓｅｄ［Ｐｏｒｐ...     

DYNAMICS OF THE LOOPER DRIVE MECHANISM ON A BLIND STITCHING MACHINE

The looper drive mechanism is a main moving part in the blind stitching machine, which is aspatial 5 bar RRRSR linkage. In this paper, a dynamic analysis of the looper drive mechanism is made by means of the ma-trix method. Two methods are adopted in the calculation of the shaking force and shaking moment, one isdone by the constraint reaction of the flame-connected kinematic parts; the other is the inertialforces of all moving links.     

VECTOR BOND GRAPH REPRESENTATION OF FINITE ELEMENT METHOD IN STRUCTURAL DYNAMICS

In this paper we have shown that the invariance of energy(kinetic energy,potential energy)and virtual work is the common feature of vector bond graph and finite element method in struc-tural dynamics.Then we have discussed the vector bond graph representation of finite elementmethod in detail,there are:(1)the transformation of reference systems,(2)the transformation ofinertia matrices,stiffness matrices and vectors of joint force,(3)verctor bond graph representationof Lagrangian dynamic equation of structure.     

THE ORIGINS AND CLASSIFICATION OF EARTHQUAKE LANDFORMS IN THE ALLUVIAL PLAINS OF EASTERN CHINA

Based on observations of earthquakes that have occurredin theplains of eastern China during recent yeas, the characteristics origins, classification and distribution patterns of earthquake landforms in alluvial plains are discussed. In such flat areas, earthquakes are capable of complete reversal of topographic gradients; minor hills can be replaced by hollows and depressions can experience uplift. The major factors influencing the development of such landforms in alluvial plain are the force of the earthquake, surface and sub-surface characteristics, the thicknesses of different subsurface layers, the height of the groundwater table and the relief. Earthquake hndforms in alluvial plains may be classified hto three main groups (1) Landforms directly associated with the liquefaction of sand hyers; (2) Landforms associated with the passage of earthquake waves; and (3) Landforms associated with earthquake structures. In turn, these categories can be further sub-divided. Through analysis of the Tangshan earthquake landforms, several characteristics of the distribuinn patterns of earthquake landforms in allu vial plains have been recognised.