KCX-1型快速齿科手机消毒器

口腔齿科手机是HBV、HCV、HIV等血液传播性疾病和消化道传染病的传播媒介。采用激光泵浦光源在辐射过程中产生的瞬间高温、丰富的光谱分布的强光作为载体,对齿科手机进行快速、彻底、无损伤的消毒灭菌。     

Mobility Analysis of Altmann Overconstrained Linkages by Modified Grübler-Kutzbach Criterion

Developing a general mobility method/formula is a hot topic lasting for more than 150 years in kinematics. It is necessary to apply any mobility method to puzzling overconstrained mechanisms for verification of its generality. Altmann linkages are such recognized puzzling mechanisms that their mobility analysis is of important significance. A necessary condition for judging a general mobility method is that the method can be fit for Altmann linkages. Firstly, this study classes Altmann linkages into 17 types in terms of the numbers and types of kinematic pairs, and then Altmann overconstrained linkages are further classified into 4 types. Secondly, the mobility of Altmann overconstrained linkages is systematically analyzed by the Modified Grübler-Kutzbach criterion based on screw theory, where passive freedoms are defined as limb passive freedoms and mechanism passive freedoms. In addition, the full-cycle mobility is judged, which overcomes the shortcoming of instantaneous property of screw theory. It is shown that Modified Grübler-Kutzbach criterion not only obtains the correct numerical mobility, but also gives the mobility character by resolving reciprocal screws for the constraint system. This study lays the foundation of verification for the generality of Modified Grübler-Kutzbach criterion. Besides, Altmann overconstrained linkages almost comprise all kinds of modern parallel mechanisms and some classical mechanisms, which provides an important reference for mechanism mobility calculation.     

脉冲电流处理过程中的相变和再结晶细化晶粒(英文)

在室温下对铸态TiAl合金和冷轧TA15合金进行高密度脉冲电流处理。应用光学金相显微镜和透射电子显微镜研究脉冲电流处理前、后试样的显微组织。实验结果表明:通过脉冲电流处理可以细化铸态TiAl基合金的晶粒,从约1000μm的原始粗大层片组织,经脉冲电流处理后可以得到尺寸为3050μm细小、均匀的晶粒。对于冷轧TA15合金,脉冲电流处理后发生了完全的再结晶,晶粒组织由原始的α板条晶粒转变为细小的α等轴晶粒。研究结果表明,脉冲电流处理是一种有效的细化晶粒方法;由于不需要热机处理所要求的挤压等变形工序和高温加热、真空保护等条件,简化了工艺过程。     

The laminar burning velocity of flames propagating in mixtures of hydrocarbons and air measured with the heat flux method

The heat flux method for stabilizing flat adiabatic flames and measuring adiabatic burning velocities is reviewed. The latest improvements of the burner construction and analysis of the measurements are presented and a reliable error estimate is deduced. A consistent and reliable set of burning velocities has been measured for a range of fuels: new results for the adiabatic burning velocities of mixtures of methane, ethane, propane, n-butane, and isobutane with air are presented, including error bars of 95% confidence intervals. The influence of variations of initial temperature on the burning velocity of mixtures of methane and air has also been studied. The results are compared with other measurements using the heat flux, counterflow, and combustion vessel methods. It seems that results for the burning velocity using different methods converge toward each other. For stoichiometric flames of methane and air this value seems to be close to 36 cm/s, while the differences between the results of different techniques do not vary by more than roughly 1 cm/s.     

合同能源管理在厦门某商场建筑节能中的应用

阐述了合同能源管理在厦门某商场建筑中的应用,根据历史能耗数据分析了该商场在冷源、水系统和照明上的节能潜力,指出商场的空调系统无法根据室内实际负荷来调节冷量输出,水泵流量与制冷机不匹配,灯具不是高效的照明系统等问题,给出了相对应的节能解决方案,并针对每种节能解决方案进行了节能量计算,尤其是对于离心式冷水机组加装VSD(Variable Speed Driver)后的节能量的计算方法进行了讨论,经过计算,得出离心式冷水机组加装VSD后在部分负荷下可以节能20%左右。     

Effect of Rare Earth on the Corrosion-Resisting Performance of Zinc-Based Alloy Coatings

The corrosion behavior of coatings of pure zinc and Zn-Al,Zn-Al-RE alloys in NaCl solu-tions was studied by salt-spray experiments,even corrosion experiments and electrochemical measurementsof bi-directional polarization curves and a.c.impedance in weak polarization region consistent regularitieswere obtained by these different methods,viz.,the corrosion resistance of Zn could be enhanced by alloying itwith Al,and particularly with Al-RE.The causes of enhancement of corrosion resistance by RE were alsodiscussed.     

高密度聚乙烯与其他聚烯烃共混物高取向薄膜结晶结构的电子显微学研究

本文用透射电子显微镜方法研究了高密度聚乙烯(HDPE)与其它聚烯烃[包括线性低密度聚乙烯(LLDPE)、低密度聚乙烯(LDPE)、等规聚丙烯(iPP)、聚丁烯-1(PB-1)等]共混物高取向薄膜的结晶结构,其中聚烯烃组分含量为10%。在共混物熔体拉伸薄膜中,HDPE以高取向的片晶形式存在,片晶的生长方向垂直于拉伸方向。共混物中LLDPE、LDPE与HDPE形成共晶。与HDPE不相容的iPP、PB-1在共混体系中未观察到明显的相区存在。聚烯烃组分的加入,不仅影响HDPE的片晶尺寸,同时影响结构的对称性,即由纯HDPE的非对称“近单晶”结构变为对称的纤维结构。     

MICROBRIDGE TESTING OF YOUNG''''S MODULUS AND RESIDUAL STRESS OF NICKEL FILM ELECTROPLATED ON SILICON WAFER

Microbridge testing is used to measure the Young's modulus and residual stresses ofmetallic films. Nickel film microbridges with widths of several hundred microns arefabricated by Microelectromechanical Systems. In order to measure the mechanicalproperties of nickel film microbridges, special shaft structure is designed to solve theproblem of getting the load--deflection curves of metal film microbridge by Nanoin--denter XP system with normal Berkovich probe. Theoretical analysis of the micro--bridge load--deflection curve is proposed to evaluate the Young's modulus and residualstress of the films simultaneously. The calculated results based on the experimentalmeasurements show that the average Young's modulus and residual stress are around190GPa and 175MPa respectively, while the Young's modulus measured by Nano-hardness method on nickel film with silicon substrate is 186.8±7.34GPa.     

十字叠层板横向剪切刚度的计算方法

本文研究了十字叠层板横向剪切刚度系数的计算方法.指出前人采用的横向剪应力为抛物线分布的假设不够准确,使C_ii的计算值产生误差.本文首先推导了横向剪应力沿厚度分布的计算公式,然后用幂级数拟合了近似权函数,用权函数法和能量法对两种铺层结构的碳/环氧十字叠层板的C_ii进行了计算.对比了两种方法的结果,并与文献[1]的方法作了对比.结果表明,对于对称层板本文权函数法与文献[1]的结果基本一致;而对于非对称叠层板,二者差别明显.能量法结果与权函数法对比,前者更精确.