Ca和Sm双原子共填充方钻矿化合物的制备及热电性能

用熔融法结合放电等离子快速烧结技术（SPS）制备了单相的Ca和Sm共填充的方钴矿化合物CamSmnFexCo4-xSb12,研究了两种原子共填充总量及填充分量对其热电性能的影响规律．结果表明：随着Ca和Sm双原子共填充总量的增加,P型CamSmnFexCo4-xSb12化合物的Seebeck系数增大、电导率和热导率降低．当共填充总量相近时,Ca原子填充分量较大的方钴矿化合物,其电性能较好;而Sm原子填充分量较大的方钴矿化合物,其热导率较低、Seebeck系数较高．Ca0.15Sm0.24Fe1.51Co2.48Sb12化合物的最大热电性能指数ZTmax值在775K时为0．85．     

N型Skutterudite化合物BayCo4Sb12的合成及热电性能

用两步固相反应法合成了单相Ba填充式skutterudite化合物BayCo4Sb12.研究了Ba对skutterudite化合物热电性能的影响与CoSb3比较电导率大幅度提高了将近20倍,并且随Ba填充分数的增加电导率增大;塞贝克Seebeck系数较CoSb3有小幅度的下降,但在中高温区域却有一定程度的提高,并且随着Ba填充分数的增加而下降;晶格热导率明显下降;对Ba填充量为0.3的Ba0.3Co4Sb12化合物得到的最大热电性能指数ZT达到0.91.     

LayFeCo3.0Sb12热电化合物的原位反应合成及热电性能

以Co、Sb、Fe及La为起始原料，采用放电等离子烧结（SPS）技术原位反应合成了填充式方钴矿化合物LayFeCo3.0Sb12（Y=0～0．4）。实验结果表明，在Y=0～0．3组成范围内，P型传导的LayFeCo3.0Sb12化合物为试样中的主晶相，并伴有极少量的Sb相；当Fe含量固定为1．0时，La的饱和填充分数达到0．3。在填充分数小于最大填充分数时，填充化合物的晶格常数随La填充分数的增加而增加。LayFeCo3.0Sb12化合物的电导率和热导率随着La填充量的增加而降低，Seebeck系数随着La填充量的增加而增加，功率因子随温度升高而升高。填充分数为0．3时，LayFeCo3.0Sb12化合物有较高的热电性能，其中在773K时具有最大的热电优值（ZT值）0．56。     

高填充量BaxEuyCo4Sb12方钴矿热电性能研究（英文）

利用熔融法和等离子放电烧结(SPS)制备单相双原子填充BaxEuyCo4Sb12方钴矿材料并测试其高温热电性能。实验发现,在高填充量下(x+y>40%),材料在高温时具有高的功率因子(>60 W/(cm K2))。在方钴矿的晶格空洞中同时引入Ba和Eu两种填充原子,能增强晶格声子散射,从而大幅降低方钴矿的晶格热导。实验证实,BaxEuyCo4Sb12体系的晶格热导显著降低,其室温晶格热导最低达1.7 W/(m K)。与此对应的是双原子填充BaxEuyCo4Sb12方钴矿材料的热电优值(ZT值)明显增大,其中Ba0.19Eu0.23Co4Sb12的ZT值在850 K时达到了1.3。     

Skutterudite化合物FexC04-xSb12的放电等离子烧结原位合成及热电性能

采用放电等离子烧结(SPS)技术在800～1000K温度范围内原位反应合成了富Co基Skutterudite化合物FexCo4-xSb12(x=0～1.0),并对化合物的结构、微观形貌及热电性能进行了研究.结果表明化合物的晶格常数随Fe含量的增加而线性增加,电导率随着Fe置换量的增加而增加,Seebeck系数的峰值随着Fe置换量的增加而向高温方向移动,热导率随Fe置换量的增加而进一步降低.对于富Co基Skutterudite化合物FexCo4-xSb12,x=1.0的Fe1.0Co3 0Sb12化合物具有较高的热电性能指数,在673K取得最大ZT值约0.3.     

Skutterudite化合物FexCO4-xSb12的放电等离子烧结原位合成及热电性能

采用放电等离子烧结(SPS)技术在 800 ~1000K温度范围内原位反应合成了富 Co基 Skutteru dite化合物FexCo4-xSb12(x=0~1.0),并对化合物的结构、微观形貌及热电性能进行了研究。结果表明化合物的晶格常数随Fe含量的增加而线性增加,电导率随着Fe置换量的增加而增加,Seebeck系数的峰值随着Fe置换量的增加而向高温方向移动,热导率随 Fe置换量的增加而进一步降低。对于富 Co基 Skutteru dite化合物FexCo4-xSb12,x=1.0 的 Fe1.0 Co3.0 Sb12化合物具有较高的热电性能指数,在 673K取得最大 ZT值约0.3。     

N型La0.9NixCo4-xSb12化合物的制备及热电性能研究

采用放电等离子烧结(SPS)方法制备了N型La0.9NixCo4-xSb12(x=0.05-1.0)化合物热电材料.借助于先进的结构和性能表征手段,系统研究了Ni含量对化合物热电性能的影响规律.实验结果表明,随着Ni含量增加,La0.9NixCo4-xSb12化合物的电阻率和Seebeck系数减小.当Ni含量x＜0.6时,化合物的热导率随Ni含量增大而降低,说明加入一定量的Ni能很好地降低材料的热导率.N型La0.9Ni0.4Co3.6Sb12化合物在温度773K时具有最大的热电性能优值(ZT)0.4558.     

La填充Ni置换n型Skutterudite热电材料的制备及性能

起始原料使用La、Co、Ni和Sb元素粉末,采用机械合金化(MA)和热压烧结(HP)的方法制备了名义成分为LaxNi0.2Co3.8Sb12(x=0.1,0.3,0.5,0.7)n型填充Skutterudite化合物热电材料,研究了不同La含量对MA-HP成型后的相组成及热电性能的影响.研究结果表明,机械合金化10h后的粉末,在650℃热压2h后可得到单相Skutterudite结构化合物;随着La填充分数的增加,晶格常数增大;通过向Skutterudite结构的空隙中填充稀土La原子,能大幅度降低热导率;热电性能研究表明,La0.5Ni0.2Co3.8Sb12在750K左右能得到最大的ZT值0.33.     

Ca和Sm双原子共填充方钴矿化合物的制备及热电性能

用熔融法结合放电等离子快速烧结技术(SPS)制备了单相的Ca和Sm共填充的方钴矿化合物Ca_mSm_nFe_xCo_4-xSb₁₂, 研究了两种原子共填充总量及填充分量对其热电性能的影响规律. 结果表明: 随着Ca和Sm双原子共填充总量的增加, p型Ca_mSm_nFe_xCo_4-xSb₁₂化合物的Seebeck系数增大、电导率和热导率降低. 当共填充总量相近时, Ca原子填充分量较大的方钴矿化合物, 其电性能较好; 而Sm原子填充分量较大的方钴矿化合物, 其热导率较低、Seebeck系数较高. Ca_0.15Sm_0.24Fe_1.51Co_2.48Sb₁₂化合物的最大热电性能指数ZT_max值在775K时为0.85.     

Ag/Sb比对（GeTe）85(AgySb2-yTe3-y)15合金热电性能的影响

按不同Ag/Sb比制备了(GeTe)85(AgySb2-yTe3-y)15(y=1.0,1.02,1.2,1.3,1.5)系列TAGS热电材料,发现偏化学计量比的样品中有Ag8GeTe6低热导率第二相的析出。改变Ag/Sb比能显著降低材料的晶格热导率,y=1.3样品的晶格热导率在700K约为基体相的40%。样品的电导率随着y值的增加先增加后减小,Seebeck系数随成分的变化规律与电导率相反,随着Ag/Sb比增加而减小。y=1.02样品在744K时获得最大ZT值1.37,与等化学计量比y=1.0样品相比提高了10%左右,且随着温度的进一步升高,ZT值有继续上升的趋势。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.