可注射磷酸钙骨水泥的研究

可注射磷酸钙骨水泥具有良好的生物相容性、骨传导性、可降解性、易操作性及可塑性等优点，临床上可用于非负重部位骨缺损的修复、药物或生物因子载体、牙根管的充填、松质骨螺钉的加固以及骨折的固定等方面，在植入学、骨创伤学及放射介入学等领域中具有广泛的应用前景。目前可注射磷酸钙骨水泥已经成为骨水泥研究中的主要课题，就其最新研究进展进行了讨论。     

磷酸钙骨水泥修复兔颅骨缺损新骨生长计算机图像分析

利用计算机图像处理技术对磷酸钙水泥修复兔颅骨缺损组织切片标本的光镜图像进行采集,对采集到的原始图像进行滤波、分割和数学开矿学等图像处理,计算不同视野新生骨生长的面积百分比,并对不同视野的结果进行生物统计分析,得到兔颅骨修复过程中新生骨定量生长情况,用计算机图像处理方法将成风过程从传统的组织形态学光镜观察的定性分析上升到了定量分析,为磷酸钙骨水泥修复骨缺损成骨机理和临床材料选择提供了定量的依据。     

聚合磷酸钙骨水泥的制备和性能研究

采用丙烯酸和衣康酸的共聚物与自制磷酸钙粉末反应制备骨水泥。用自凝牙托水对类磷酸四钙（TTCP）粉末进行表面改性后所制备的骨水泥,初凝时间为4．5min,终凝时间为8.5min,抗压强度可达４２MPa。采用类TTCPα－磷酸三钙的混合粉料制备的骨水泥,初凝时间为５．５min,终凝时间为１１．０min,抗压强度可达４３MPa。     

针状硅灰石对磷酸盐骨水泥性能的影响

以磷酸氢二钾和磷酸二氢钾为固化液,以磷酸四钙、α-磷酸三钙、磷酸氢钙、焦磷酸钙、羟基磷灰石和碳酸钙为原料合成骨水泥,向其添加针状硅灰石,研究了针状硅灰石对其性能的影响。结果表明,在磷酸钙骨水泥中添加针状硅灰石可以缩短凝结时间,提高抗压强度。当针状硅灰石的添加量为3%,骨水泥性能达到最佳;其初凝时间、终凝时间分别为14和28 min,样品在Ringer’s模拟液溶液中浸泡2周后抗压强度达49.23 MPa,浸泡液的pH值变化幅度小(7.1~7.8),在安全范围之内。     

熟料粒度对骨粉/磷酸钙生物骨水泥结构与性能的影响

采用新方法首次将动物骨中的鱼骨引入到磷酸三钙和磷酸氢钙等原料体系中通过高温烧结制备磷酸钙基生物骨水泥（CPC）,以柠檬酸和柠檬酸钠的缓冲液为固化液、按一定的液固比制备固化试样,通过扫描电子显微分析（SEM）和力学性能测试等方法,研究了熟料粒度对其固化试样结构与抗压强度的影响.结果表明：制备过程中骨水泥粉末的粒度对其固化试样的微观结构及其抗压强度有着较为显著的影响,通过调整骨水泥粉末的粒度可达到优化其固化试样的微观结构和改善其力学性能的目的.     

MDF水泥的碳纤维增强研究

研究了碳纤维和为ＭＤＦ水泥增强材料的可行性以及它的增强效果,探讨了各种因素对ＭＤＦ水泥性能的影响,分析了碳纤维增强ＭＤＦ材料的结构特征。研究结果表明,碳纤维作为ＭＤＦ水泥的增强材料能够显著提高ＭＤＦ水泥的抗弯强度、断裂韧性和耐水性能。碳纤维在复合材料中呈三维均匀分布,形成空间网络结构,这是碳纤维增强ＭＤＦ水泥的主要原因。     

MDF水泥的碳纤维增强研究

研究了碳纤维作为MDF水泥增强材料的可行性以及它的增强效果．探讨了各种因素对MDF水泥性能的影响,分析了碳纤维增强MDF材料的结构特征．研究结果表明,碳纤维作为MDF水泥的增强材料能够显著提高MDF水泥的抗弯强度、断裂韧性和耐水性能。碳纤维在复合材料中呈三维均匀分布．形成空间网络结构,这是碳纤维增强MDF水泥的主要原因。     

表面改性碳纤维增强MDF水泥及其机理研究

采用了两种方法对碳纤维进行了表面改性处理，并对碳纤维与ＭＤＦ水泥的界面粘结进行了ＳＥＭ、ＩＲ等研究。研究结果表明，通过对碳纤维表面进行了氧化或氧化加偶联处理，均能提高碳纤维对ＭＤＦ水泥的增强效果，而以氧化加偶联处理碳纤维方法为最优。     

碳纤维增强水泥压敏效应AC测试方法探讨

碳纤维增强水泥(CFRC)的导电性与其自身的变形有关,用交流(AC)阻抗测试法,研究了碳纤维增强水泥的压敏效应,并与直流电阻测试法作了比较.结果表明,交流阻抗测试法同样能反映试样受载变形的全过程,而且测试数据更稳定,灵敏度更高,并且从导电机理上进行了分析.     

Augmentation of pedicle screw fixation with calcium phosphate cement

To determine whether a biodegradable calcium phosphate cement (CPC) provides significant augmentation of pedide screw fixation or not, an in vitro biomechanical study was carried out to evalwate the biomechanical effea of CPC in the restoration and angmentation of pedide screw.fixation. Axial pullout and cyclic beruding resistance test were employed in the experiment, and polymethylmethacrylate (PMMA) was chosen as control. The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group, but less than those of PMMA restoration group ard aygmentation group respectively ( increased by 126% versus control). In cyclic bending resistance test, the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.     

Resistance Responses of Carbon Fiber Cement to Cycled Compressive Stresses

1Introduction Thestudyofthecement basedmaterialswithcarbon fibershaslastedmorethanonedecade.Carbonfiberisa high performanceandmulti functionalreinforcementma terial.Itpossessesaseriesofexcellentcharacteristics,suchaslowthermalexpansion,highelectricalcondu…     

Microstructure and mechanical properties of calcium phosphate cement/gelatine composite scaffold with oriented pore structure for bone tissue engineering

The macroporous calcium phosphate(CPC) cement with oriented pore structure was prepared by freeze casting. SEM observation showed that the macropores in the porous calcium phosphate cement were interconnected aligned along the ice growth direction. The porosity of the as-prepared porous CPC was measured to be 87.6% by Archimede’s principle. XRD patterns of specimens showed that poorly crystallized hydroxyapatite was the main phase present in the hydrated porous calcium phosphate cement. To improve the mechanical properties of the CPC scaffold, the 15% gelatine solution was infiltrated into the pores under vacuum and then the samples were freeze dried to form the CPC/gelatine composite scaffolds. After reinforced with gelatine, the compressive strength of CPC/gelatine composite increased to 5.12 MPa, around fifty times greater than that of the unreinforced macroporous CPC scaffold, which was only 0.1 MPa. And the toughness of the scaffold has been greatly improved via the gelatine reinforcement with a much greater fracture strain. SEM examination of the specimens indicated good bonding between the cement and gelatine. Participating the external load by the deformable gelatine, patching the defects of the CPC pores wall, and crack deflection were supposed to be the reinforcement mechanisms. In conclusion, the calcium phosphate cement/gelatine composite with oriented pore structure prepared in this work might be a potential scaffold for bone tissue engineering.     

Electrical resistance and microstructure of latex modified carbon fiber reinforced cement composites

The electrical resistance,flexural strength,and microstructure of carbon fiber reinforced cement composites(CFRC) were improved greatly by adding water-redispersible latex powder.The electrical resistance of CFRC was investigated by two-probe method.The input range of CFRC based strain sensors was therefore increased,whereas electrical resistance was increased and remained in the perfect range of CFRC sensors.The analysis of scanning electron microscopy indicated that elastic latex bridges and a latex layer existed among the interspaces of the adjacent cement hydration products which were responsible for the enhancement of the flexural strength and electrical resistance.The formation mechanism of the elastic latex bridges was also discussed in detail.The continuous moving of two opposite interfaces of the latex solution-air along the interspaces of the adjacent hydrated crystals or colloids was attributed to the formation of the elastic latex bridges.     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸/磷酸氢钾复合固化液混合制得玻璃基生物骨水泥(GBC),利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石(HA)晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7 d时达到最大值,骨水泥呈现多孔结构。     

Mechanism of functional responses to loading of carbon fiber reinforced cement-based composites

Single fiber pull-out testing was conducted to study the origin of the functional responses to loading of carbon fiber reinforced cement-based composites. The variation of electrical resistance with the bonding force on the fiber-matrix interface was measured. Single fiber electromechanical testing was also conducted by measuring the electrical resistance under static tension. Comparison of the results shows that the resistance increasing during single fiber pull-out is mainly due to the changes at the interface. The conduction mechanism of the composite can be explained by the tunneling model. The interfacial stress causes the deformation of interfacial structure and the interfacial debonding, which have influences on the tunneling effect and result in the change of resistance.     

Influence of surface treatment of carbon fibers on electrochemical crystallization of calcium phosphate

1　INTRODUCTIONCalcium phosphates have been widely studiedas an implant material for many years due to theirsimilarity in chemical composition and high bio compatibility with natural bone tissue. But theyare very brittle. Some of the prospective bio ceramic materials with biocompatibility but weaklymechanical propertles, such as hydroxyapatite(HA) or tricalcium phosphate ( TCP), are rein forced with metal[1], ceramic[2], polymer[3], car bon fiber[4] or…     

AW玻璃基骨水泥的制备及其结构性能表征

以AW生物玻璃与柠檬酸／磷酸氢钾复合固化液混合制得玻璃基生物骨水泥（GBC）,利用XRD、FTIR和SEM对GBC的产物晶相、化学组成和显微结构进行了分析,并对其力学性能进行了测试。结果表明,GBC在固化反应后就已经有羟基磷灰石（HA）晶相生成;随着GBC在SBF中浸泡时间的延长,又生成了少量碳酸钙晶体,且HA晶相数量增多,抗压强度在7d时达到最大值,骨水泥呈现多孔结构。     

碳纤维机敏混凝土材料的研究与进展

碳纤维混凝土是在普通混凝土中均匀地加入短切碳纤维而构成的纤维增强水泥基复合材料，与普通混凝土相比，它不仅抗拉强度高、极限抗拉应变大，而且还具有温度和压力的自感知及电磁屏蔽等特性，是土木工程界新型的功能材料，在大型土木工程结构和基础设施的健康监测以及电子设备的电磁屏蔽等领域具有广泛的应用前景。