血小板衍生生长因子、骨保护素对体外培养成骨细胞的功能影响

目的:研究血小板衍生生长因子(platelet-derivedgrowthfactor ,PDGF)对成骨细胞(osteoblast,OB)的功能影响及PDGF与骨保护素(os teoprotegerin ,OPG)在成骨细胞中表达的关系。方法:用酶消化和组织块移行生长相结合的方法,从幼兔颅骨中分离出成骨细胞进行培养,应用组织学和酶细胞化学对其生物学特性进行鉴定,兔抗PDGF -BB、OPG抗体诱导培养成骨细胞,分析成骨细胞的增殖、分化、矿化及OPGmRNA表达。结果:PDGF -BB抗体组与对照组在成骨细胞的分化成熟及OPGmRAN表达方面有显著差异(P <0 .0 1)。结论:PDGF -BB抗体可抑制OB的分化成熟、骨质形成及OPGmRAN的表达。     

片式引线框架镀银设备的研制

引线框架的主要功能是为芯片提供机械支撑载体,并作为导电介质连接IC外部电路,传送电信号,以及与封装材料一起,向外散发芯片工作时产生的热量.在介绍引线框架在IC封装中的作用基础上,主要介绍了片式引线框架镀银设备的工作原理、主要结构及控制系统,同时简单阐述了引线框架材料、技术现状及发展趋势.     

偏光片周边的镜面磨削工艺

偏光片是液晶显示器的主要原材料之一,约占其制造成本的20%～30%,介绍了偏光片的基本结构和偏光片周边的镜面磨削工艺,该工艺是对裁切好的偏光片的周边进行精磨的工艺过程,使之达到要求的光洁度以及精确的尺寸和角度.     

基于联合变换相关器的像移测量仿真分析

对基于联合变换相关器的像移测量数学原理进行了说明,介绍了面阵CCD的安装位置以及输入图像的获取方法,分析了低信噪比输入图像、相对转动位移对测量精度的影响。应用MATLAB对输入图像进行傅里叶变换得到联合功率谱,对二值化处理的功率谱进行傅里叶变换得到相关输出,用质量中心算法计算出像移量。分析得出,输入图像信噪比大于5dB,测量均方误差小于0.05像素;输入图像相对转动位移在0.1°的范围内,转动位移对测量精度和峰噪比的影响可以忽略不计。综合分析表明像移测量均方误差小于0.05像素。     

NEAR-UV ACTIVATION OF ENZYMATIC CONVERSION OF 5-HYDROXYTRYPTOPHAN TO SEROTONIN

Near-UV (337 nm) photoactivation of the 5-hydroxytryptophan decarboxylation reaction producing serotonin has been observed. The photoactivation effect was investigated as a function of fluence rate and fluence, and pH. Photoactivation of decarboxylase activity was found to occur at nearly neutral pH values (low activity of the enzyme in the dark). The findings indicate that the effect of light is similar to a pH shift toward the acid region, which causes the enzyme conversion from the inactive to active form. Pyridoxal phosphate, the decarboxylase cofactor, in the form of an adduct absorbing at 330-340 nm, is suggested as a candidate for the role of the photoactive chromophore of decarboxylase.     

Transition Metal Ion-binding Properties of a 14-Membered N2O2S2- Macrobicyclic Ligand

The selective liquid–liquid extraction of various transition metal cations from the aqueous phase to the organic phase was carried out using a 14-membered N₂O₂S₂-macrobicycle. Metal picrates such as Pb²⁺, Co²⁺, Zn²⁺, Ni²⁺,Cu²⁺ and Cd²⁺ were used in this extraction studies. It was found that the ligand showed moderate selectivity towards Pb²⁺ only among the other metals. The extraction constant (log K _ex) was determined to be 13.8 for Pb²⁺ complex.     

喷镀系统在凸点制备中的应用

介绍了利用电镀法制造晶圆凸点的典型工艺和喷镀设备.喷镀系统是凸点电镀设备中最关健的部件.通过计算机软件模拟试验,对喷镀系统中的喷杯体和匀流板等各种参数和位置进行了优化设计,并在设备上应用验证.该系统在凸点电镀设备上应用后,在晶圆片上成功做出了高质量的均匀凸点,取得了良好效果.     

How Far Are We from Making Metamaterials by Self‐Organization? The Microstructure of Highly Anisotropic Particles with an SRR‐Like Geometry

Metamaterials offer new unusual electromagnetic properties, which have already been demonstrated, and many postulated new functionalities are yet to be realized. Currently, however, metamaterials are mostly limited by narrow band behavior, high losses, and limitation in making genuinely 3D materials. In order to overcome these problems an overlap between metamaterial concepts and materials science is necessary. Engineered self‐organization is presented as a future approach to metamaterial manufacturing. Using directional solidification of eutectics, the first experimental realization of self‐organized particles with a split‐ring resonator‐like cross section is demonstrated. This unusual morphology/microstructure of the eutectic composite has a fractal character. With the use of TEM and XRD the clear influence of the atomic crystal arrangement on the microstructure geometry is presented. The materials obtained present very high anisotropy and can be obtained in large pieces. Metallodielectric structures can be created by etching and filling the space with metal. The next steps in the development of self‐organized materials exhibiting unusual properties are discussed.     

Equivalent parameters of a Josephson junction in a microwave SQUID structure

The equivalent parameters of a Josephson junction in a microwave SQUID structure are calculated on the basis of relations obtained as a result of an analysis of the operation of an rf SQUID. This analysis is based on the sawtooth variation of the voltage on the resonator as a function of the constant flux bias. The quantitative characteristics permit regarding the Josephson junction as a linear impedance in the rf or microwave circuit, whose real and imaginary parts are controlled by the constant magnetic flux passing through the SQUID loop. Zh. Tekh. Fiz. 69, 106–112 (November 1999)     

The I2(B) predissociation by solving an inverse atoms-in-molecule problem

The valence electronic states of the iodine molecule are analysed by means of a simple atoms-in-molecule model which accounts for the lowest ²P states of iodine atoms and approximates the spin-orbit interaction by its atomic part. For this model, an inverse problem is solved, i.e. non-relativistic potential energy curves and diabatic couplings are determined by a least-squares fit to known relativistic potential energy curves. The resulting adiabatic wave functions are used to calculate the electronic matrix elements responsible for natural, hyperfine and magnetic predissociation of the iodine molecule in the B0⁺ _u: state. The results are in reasonable agreement with experimental data, being stable enough with respect to the variation of input relativistic potentials. They also indicate the importance of diabatic couplings between the non-relativistic states of the same symmetry.