SiO_2对磷酸盐玻璃晶化性能的影响

磷酸盐系统是生物活性微晶玻璃常用系统之一。本文研究了Ｎａ２Ｏ－ＣａＯ－ＡＩ２Ｏ３－Ｐ２Ｏ５系统玻璃引入ＳｉＯ２。前后的晶化性能，以讨论ＳｉＯ２对系统玻璃晶化行为的影响。本文利用ＤＴＡ，ＳＥＭ，ＸＲＤ，ＥＰ－ＭＡ，ＦＴ－ＩＲ等手段进行了研究。研究发现：ＳｉＯ２能促进ＡｌＰＯ４晶体的析出，并且使系统产生分相进而改善了该系统玻璃的晶化特性。     

Fe73.5Cu1Nb2Si13.5B9Ni1非晶合金的晶化动力学研究

利用差示扫描量热法（DSC）研究了Fe73.5Cu1Nb2Si13.5B9Ni1非晶的纳米晶化动力学。结果表明,晶化过程分为两步完成,晶化初生相为Fe3Si.第一晶化过程的晶化开始温度Tx1、峰值温度Tp1与扫描速度β的对数之间存在着线性关系,分别为：Tx1=736.52＋8.67lnβ和Tp1=743.9＋12.7lnβ.采用Kissinger方法和Ozawa方法计算Fe73.5Cu1Nb2Si13.5B9Ni1非晶合金晶化的表观激活能Eа分别为435.2kJ/mol和441.1 kJ/mol,而成分为Fe73.5Cu1Nb3Si13.5B9的表观激活能大约为410 kJ/mol,表明Ni部分替代Nb后合金的热稳定性提高。第一晶化反应的局域激活能Ec（α）随晶化体积分数α不断下降,Avrami指数表明该非晶合金的晶化为扩散控制的三维晶粒长大过程。探讨了用Ni元素部分替代Finemet合金中Nb元素后非晶合金热稳定性提高的原因。     

两种稀土基大块非晶合金非等温晶化行为的研究

以不同加热速率下的DSC曲线数据为基础,利用Kissinger及Deloy激活能计算方法研究了Mm55Al25Cu10Ni5Co5与La55Al25Cu10Ni5Co5大块非晶合金的非等温晶化动力学。结果表明:两非晶合金的玻璃转变温度(Tg)、晶化初始温度(Tx)和晶化峰值温度(Tp)都随着加热速率的增加而增加,具有明显的动力学效应;阶段激活能随晶化体积分数的增加,先迅速增加,达到最大值后缓慢下降,为典型的形核及长大机制且形核瞬间完成,晶化以生长为主。Mm55Al25Cu10Ni5Co5非晶合金的玻璃转变激活能、形核激活能和长大激活能以及晶化初期激活能和最大激活能都相应大于La55Al25Cu10Ni5Co5表明前者比后者具有更高的热稳定性。     

Alkaline treatment kinetics of calcium phosphate by piezoelectric quartz crystal impedance

Calcium phosphate film was prepared by electrochemical deposition technology. Subsequently, the alkaline treatment process of calcium phosphate film in 0.1 mol/L NaOH solution was monitored on real time by the piezoelectric quartz crystal impedance (PQCI) technique. The variations of morphology and composition for the alkaline treatment products were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) and X-ray diffraction (XRD), respectively. The dynamic variations of calcium phosphate can be characterized by the change of equivalent circuit parameters. The results show that the forming process of hydroxyapatite (HA) is composed of three stages: (1) acidic calcium phosphate dissolution; (2) phase transformation; and (3) HA formation. Furthermore, the correlative kinetic equations and parameters are obtained by fitting the static capacitance (C _s)—time curves. Foundation item: Project(2005CB623901) supported by the Major State Basic Research and Development Program of China     

镁基大块非晶合金的制备与性能研究

采用铜模浇铸的方法成功制备了最大直径为12mm的Mg65Cu20Ag5Gd10非晶合金,并对其结构、热稳定性能、非晶形成能力、压缩性能及断口形貌进行了分析.结果表明,Mg65Cu20Ag5Gd10具有较强的玻璃形成能力和良好的热稳定性能;合金的断裂强度达895MPa,弹性应变为2.35%.     

Study on the protection of Er-doped phosphate glass waveguide surface in ion-exchange processing

A novel method, sputtering K9 glass film, is proposed to solve the surface corrosion of Er-doped phosphate glass during ion-exchange processing for optical waveguide fabrication. The corrosion causes are analyzed to be the intrinsically weak stabilization of phosphate glass structure, hydrophile and weakly acidic property of phosphate radical. Experimental results show that the K9 glass film could not only protect the Er-doped phosphate glass surface from being corroded but also give no influence on the waveguide fabrication. The effect of thickness of K9 glass film on the optical property of waveguide is also investigated and the optimal thickness is found to be 60–80 nm. It provides a good base for further fabrication of active phosphate glass optical waveguide devices. Supported by the Optical Science and Technology Foundation of Shanghai Technology Committee (Grant No. 022261009), the Young Teacher Cultivation Foundation of Dalian University of Technology (Grant No. 893210), and the Doctor Startup Foundation of Dalian University of Technology (Grant No. 893322)     

Luminescent properties of Ce3+ ions in zinc phosphate glass prepared in air

Glasses are prepared by sintering P2O5, ZnO and Ce2(C2O4)3 10H2O mixtures at 1 100 ℃ in air and then annealed at 400 ℃ for 10 hours. The obtained glasses are homogeneous, transparent and colorless. Emission and excitation spectra are measured for the samples and the results show that the glasses contain Ce3+ trivalent cerium ions. The parameters of glass preparation obtained here may be adapted to preparing this type of glasses doped with other lanthanide ions, so as to study energy transfer phenomena and variation of radiative lifetime with refractive index due to local field effect.     

含镁磷酸盐熔融还原制磷的动力学

以纯磷酸钙、氧化钙、二氧化硅、氧化铝和氧化镁为原料配矿,固体石墨为还原剂,进行磷矿还原反应。熔渣中五氧化二磷含量用磷钼酸喹啉质量法分析,考查了不同反应时间、不同温度、不同酸度对还原率的影响.结果表明:反应温度越高、反应时间越长,还原率越高;配矿中酸度mk=1.15时的还原率较mk=0.85、0.75高,而mk=0.75时的还原率增幅最大.对固体碳还原磷酸盐的反应进行了动力学拟合,得到静置条件下固体碳还原配矿中磷酸盐的表观反应速率常数的表达式,证实了在高温反应条件下,磷矿还原反应为扩散控制过程.     

Crystallization behavior of Fe_(78)Si_(13)B_9 metallic glass under high magnetic field

The effects of high magnetic field on the crystallization behavior of the Fe78Si13B9 metallic glass ribbon were studied. The samples were isothermal annealed for 30 min under high magnetic field and no field,respectively. Microstructure transformation during crystallization was identified by X-ray diffraction and transmission electron microscopy. It was found that the crystallizations of Fe78Si13B9 metallic glass processed under different conditions were that the precipitation of dendrite α-Fe(Si) and spher...     

Crystallization of Pd40Cu30Ni10P20 bulk metallic glass with and without pressure

The glass-transition behavior of Pd40Cu30Ni10P20 bulk metallic glass was investigated by differential scanning calorimetry （DSC） and X-ray powder diffraction （XRD）. The effect of pressure on the crystallization behavior of Pd40Cu30Ni10P20 bulk glass was studied by in situ high-pressure and high-temperature X-ray powder diffraction using synchrotron radiation. Phase analyses show at least six crystalline phases in the crystallized sample, namely, monoclinic, tetragonal CuaPd-like, rhombohedral, fcc-Ni2Pd2P, fcc-（Ni, Pd） solid solution, and body-centered tetragonal （bct） NiaP-like phases. The onset crystallization temperature increases with pressure having a slope of 1 1 K/GPa in the range of 0 to 4 GPa. The results are attributed to the competing process between the thermodynamic potential barrier and the diffusion activation energy under pressure.     

Preparation of calcium phosphate coating on pure titanium substrate by electrodeposition method

The influences of pH value, electrolyte temperature and loading time on depositing calcium phosphate coating on pure titanium substrate by electrodeposition process were investigated. The process was carried out with an electrochemical work-station supplying a direct current power at potential of -0.8V (vs SCE). The electrolyte consists of 7 mmol·L-1 CaCl2·2H2O, 3 mmol·L-1 Ca(H2PO4)2·H2O and 2.5% H2O2. NaOH and HCl solutions were used to adjust pH value. The deposited samples were characterized by X-ray diffraction and scanning electron microscope. The comparison of the deposits obtained at lower and higher pH values demonstrates that the crystallization process at the interface is favoured by high pH value. With temperature increasing, the deposited hydroxyapatite is occasionally of plate-like shape, and the width and the length of the deposited calcium phosphates at 65 ℃ are larger than those at 55 ℃. Therefore, it is confirmed that the morphology and microstructure of electrochemically deposited calcium phosphates can be regulated. Additionally, the coating formed in electrolyte with H2O2 additive is homogeneous and the evolution of H2 bubble can be eliminated.     

新型亚芳基双[二(季戊四醇磷酸酯)磷酸酯]阻燃剂的合成、表征与热稳定性

许多领域使用的高分子材料需要添加阻燃剂赋予其阻燃性能。磷化合物是重要的有机阻燃剂,其阻燃功能与含磷有机化合物的结构、磷含量及热稳定性能等有关。基于此,以季戊四醇、三氯氧磷、间苯二酚、双酚A为主要原料,合成了两个新型磷系阻燃剂亚芳基双[二(季戊四醇磷酸酯)磷酸酯],采用元素分析、红外和氢核磁共振等分析技术表征了产物的结构。热失重分析表明,间苯二酚双[二(季戊四醇磷酸酯)磷酸酯]质量损失5wt%时的温度在350℃左右,600℃残余量高达57.6%,具有较好的热稳定性和结炭性能。     

x射线衍射法分析BAS（BaO－Al_2O_3－SiO_2）凝胶玻璃的等温结晶过程

根据ｘ射线定量分析的基本原理，采用不同比例晶相和非晶相混合试样中非晶散射峰和纯非晶试样散射峰的积分强度比建立定标曲线，其最大误差＜６％，并且首次用这条定标曲线测定了由醇盐水解法合成的ＢＡＳ凝胶玻璃（成分为ＢａＯ：３７％，Ａｌ２Ｏ３：２６％，ＳｉＯ２：３７％）在等温结晶过程中的晶相体积分数．结果与分析表明，ＢＡＳ凝胶玻璃的等温结晶过程可以用ＪＭＡ方程描述．由于ＢＡＳ凝胶玻璃有大量的表面，形核激活能小，形核快，因而结晶激活能（４４５ｋＪ／ｍｏｌ）小于成分接近的普通熔化ＢＡＳ玻璃的结晶激活能（５４３ＫＪ／ｍｏｌ），阿弗罗米指数平均约２．５５，呈现整体结晶特性，可以获得晶粒尺寸≈０．５μｍ的钡长石玻璃陶瓷．     

采用差示扫描量热法(DSC)对TDE-85/70#酸酐体系固化动力学的研究

利用差示扫描量热法（DSC）和极值法对TDE-85型环氧树酯／70#酸酐体系固化动力学进行了研究，求得了体系的固化动力学参数，并对固化反应机理进行了初步探讨．结果表明：适量的苯胺促进剂将有效地加速固化反应并降低固化反应的活化能．     

Effect of nucleating agent on the crystallization of tailings glass ceramics prepared by one-time sintering

Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings. On the basis of quaternary system of CaO-MgO-Al₂O₃-SiO₂, using DTA, XRD and SEM, the effects of different nucleating agents and mixing amounts as well as heat treatment on the crystallization of tailings glass ceramics were studied. The experimental results show that, nucleating agent and heat treatment are two necessary conditions for one-time sintering preparation of tailings glass ceramics namely, only adding nucleating agent or experiencing heat treatment, the quaternary system can not crystallize. The composite nucleating agent consisting of Cr₂O₃ and TiO₂ can further lead to the crystallization of the CaO-MgO-Al₂O₃-SiO₂ quaternary system at the lower temperature, with the major phase of diopside. In the range of mass content, 0%–4%, crystal intensity and crystal content grow. But when mass content is more than 4%, the crystal size will become coarser and the crystal distribution will be less regular. Different heat treatment regimes do not change the composition of the crystalline major phase in the glass ceramics crystallization of CaO-MgO-Al₂O₃-SiO₂ system. In the range of 30–60 minutes, with the extension of nucleation and crystallization, crystallization degree enhanced, but if the holding time surpasses 60 minutes, the crystallization is worse. Funded by The National Key Technology R & D Program of China for the 11^th Five-Year Plan(2006BAJ04A04)     

光学玻璃电流传感头温度特性分析

建立了光学玻璃电流传感头的热学模型,用有限元的方法及有限元分析软件ANSYS定量的分析了周围环境温度变化对光学玻璃电流传感头及传感光路上温度分布的影响情况,给出了光学玻璃电流传感头的等温线分布以及传感光路上的温度分布情况.研究结果表明:当周围环境温度在-40～40 ℃范围内变化时,光学电流传感头上温度分布将会变化,但温度梯度变化不大,最大的温度梯度仅为3 ℃左右;传感光路上的温度分布也将变化80 ℃左右,同样光路上的温度梯度较小,不会超过2 ℃.故制作光学玻璃传感头时,应考虑周围环境温度变化对整个系统所带来的影响.