反应溅射TiO_2薄膜

报道了反应溅射沉积ＴｉＯ２薄膜，得到ＴｉＯ２薄膜的特性如沉积速率、透射率、导电性能、吸收系数等与反应气体的流量、溅射功率有关。通过控制氧气的流量，得到具有良好导电性能和一定吸收的特殊性能的ＴｉＯ２薄膜。     

液相添加剂对PTCR陶瓷电性能的影响

液相添加剂ＡＳＴ（Ａｌ２Ｏ３＋ＳｉＯ２＋ＴｉＯ２）对ＢａＴｉＯ３陶瓷材料电性能的影响很大，随着Ａｌ２Ｏ３含量的增加，材料的电性能降低；ＳｉＯ２、ＴｉＯ２的物理特性对材料电性能影响较大；过量ＴｉＯ２对材料ＰＴＣ效应有重要影响，适当过量ＴｉＯ２含量，可得到性能优良的ＰＴＣＲ陶瓷。     

利用单片机构成的零漂动校正最佳增益放大器

利用单片机控制放大增益，使放大器的增益从２＾０，２＾２，２＾４－２＾１４共有８个可选值，使输入信号在８４ｄｂ的范围内，经最佳增益放大后，输出落入到事先设定的一个窗口范围之内，同时得到数字化的最佳增益碱。并利用单片机对零漂进行自动跟踪补偿校正。     

化学氧碘激光器中O_2（~1△g）的气相传输规律

本文通过对Ｏ２（１△ｇ）气相传输动力学的分析，得到了Ｏ２（１△ｇ）的气相传输规律，并进一步对Ｒｉｃｈａｒｄｓｏｎ、Ｔａｋｅｈｉｓａ等人的实验结果进行了分析，得到了统一的结论。     

化学氧碘激光器中O2（^1△g）的气相传输规律

本文通过对Ｏ２（＾１△ｇ）气相传输动力学的分析，得到了Ｏ２（＾１△ｇ）的气相传输规律，并进一步对Ｒｉｃｈａｒｄｓｏｎ、Ｔａｋｅｈｉｓａ等人的实验结果进行了分析，得到了统一的结论。     

基于模块化结构的N位加法器的测试生成

针对单个ｓｔｕｃｋ－ａｔ故障，研究了Ｎ位加法器的测试矢量生成问题，对于行波进位加法器，只需８个测试矢量就可得到１００％的故障覆盖率；对于Ｎ位先行进位加法器，只需Ｎ＾２＋２Ｎ＋３个测试矢量即可得到１００％的故障覆盖率。     

SrS：Ce蓝色薄膜电致发光

用Ｈ２还原法制备了ＳｒＳ：Ｃｅ蓝色发光材料，研究了它的光谱特性，并用不同掺杂浓度比较了Ｈ２还原法和ＣＳ２还原法，得到了掺杂的浓度范围，研究了Ｈ２气氛下处理温度对器件发光的影响。制得了最高亮度为２２０ｃｄ／ｍ＾２，流明效率为０．１８１ｍ／Ｗ的蓝色发光器件。     

内腔式M^2e〈1的CO2激光器

本文报道一种等效光束质量因子Ｍ＾２ｅ〈１的ＣＯ２激光器已研制成功，其束中心亮度比ＴＥＭ００模的亮度高约３倍，发散小２～３倍，输出功率与同尺寸多模激光器相比仅低５～１０％，得到了国际上首批超衍射极限输出的ＣＯ２激光器。     

电子级金红石型TiO_2生产工艺的改进

对ＴｉＣｌ４水解法生产ＴｉＯ２的生产工艺进行了改进，结果ＴｉＯ２的物理特性，诸如晶型、颗粒形状、粒度分布及平均粒径得到改善。     

双晶体谐振器振荡器的相位噪声特性

本文详细地讨论了双晶体谐振荡器（双晶振荡器）的相位噪声特性。对于闪变噪声而言，由于双晶体谐振器短期频率噪声的互不相干性，噪声指标将得到１０ｌｏｇ２或２０ｌｏｇ２的改善，对于白底噪声而言，由于双晶体谐振器总驱动电平的增加，噪声指标将得到１０ｌｏｇ２的改善。双晶振荡器的实验数据也证实了上述的理论，同时，本文还给出了双晶振荡器的温补特性和宽压控频率范围特性。     

Diagnosis of Dental Caries Using Terahertz Technology

Recently, the diagnoses of dental caries and other dental issues are in a queue as only X-ray-based techniques are available in most hospitals around the world. Terahertz (THz) parametric imaging (TPI) is the latest technology that can be applied for medical applications, especially dental caries. This technology is harmless and thus suitable for biological samples owing to the low energy of THz emission. In this paper, a developed TPI system is used to investigate the two-dimensional (2D) and three-dimensional (3D) images of different samples from human teeth. After analyzing the measured images of human teeth, the results suggest that the THz parametric technology is capable of investigating the inner side structure of the teeth. This technique can be useful in detecting the defects in all types of human and animal teeth. The measurement and analytical calculations have been performed by using the TPI system and MATLAB, respectively, and both are in good agreement. The characteristics of THz waves and their interactions with the tooth samples are summarized. And the available THz-based technologies, such as TPI, and their potential applications of diagnoses are also presented.     

Diagnosis of dental problem by using terahertz technology

Recently the diagnoses of dental caries and other dental issues are in a queue as only X-ray-based techniques are available in most hospitals around the world. Terahertz (THz) parametric imaging (TPI) is the latest technology that can be applied for medical applications, especially dental caries. This technology is harmless and thus suitable for biological samples owing to the low energy of THz emission. In this paper, a developed TPI system is used to investigate the two-dimensional (2D) and three-dimensional (3D) images of different samples from human teeth. After analyzing the measured images of the human tooth, the results suggest that the novel THz parametric technology is capable of investigating the inner side structure of the teeth. The technique can be useful in detecting the defects in all types of human and animal teeth. The measurement and analytical calculations have been performed by using the TPI system and MATLAB, respectively, and both are in good agreement. The characteristics of THz waves and their interactions with the tooth samples are summarized. And the available THz-based technologies, such as TPI, and their potential applications of diagnoses are also presented.     

Finite element simulation for laser-induced SAW propagation in tooth

Laser ultrasonic technology, a noncontact nondestructive evaluation method, can be applied to evaluating the properties of human teeth. With a finite element method, this paper studies laser induced surface acoustic wave (LSAW) characteristics propagating in human teeth. Setting up a theory model for laser-introduced surface acoustic wave (SAW) propagating in human incisors, it discusses the temperature field induced by laser irradiate in dental surface, as well as the effects of inhomogeneous enamel and early dental caries (white spot lesion) on LSAWs. Studies in this letter can provide a theoretical basis for nondestructive evaluation of human teeth with laser ultrasonic technology.     

人牙髓中MMP-2与MMP-9受正畸力作用影响的初步分析

目的：采用免疫组织化学方法,研究接受正畸力作用影响的人牙髓中MMP-2和MMP-9的表达。方法：选取接受正畸治疗的患者10名,于正畸治疗前确定应拔除的正畸牙,对其一侧选用常规正畸加力,另一侧健康同名牙不施加任何正畸力,作为同源对照,加力1d后至7d内拔除该正畸牙,各20颗,共40颗,分为加力组和对照组;选取临床诊断有牙髓炎症且无保留价值的第3磨牙20例,分为炎症组;对标本进行处理后制成切片,采用SP法,对其中MMP-2和MMP-9的表达进行图像分析和半定量分析。结果：对照组、加力组和炎症组牙髓均可见MMP-2和MMP-9的表达;在接受正畸力的牙髓组织,成牙本质细胞和牙髓成纤维细胞可见MMP-2和MMP-9表达,加力组牙髓中两者为表达增强,并且其表达强于同源对照正常的牙髓,但弱于炎症牙髓,三组差异具有统计学意义（P〈0.05）。结论：MMP-2和MMP-9在人牙髓中主要表达于成牙本质细胞和牙髓成纤维细胞的胞质中;生理条件下两者的水平较低,在接受正畸治疗时,由于受正畸力影响,牙髓处于应激状态,两者表达增强,应引起口腔医师的高度重视。     

Electron microscopical evaluation of connective tissue healing to periodontally involved teeth.

The present study was undertaken to examine if our novel root treatment for human periodontally involved teeth can facilitate a new connective tissue attachment. The novel treatment was in two parts: 1) planning and surface decalcification with citric acid on the coronal quarter of the exposed root corresponding to pocket, and 2) curettage of superficial cementum of the apical three quarters of the exposed root. The interface of the root surface and regenerating connective tissue was observed 2 and 3 weeks after surgery by light and electron microscopy. The apical migration of junctional epithelium was effectively prevented. The fibroblasts synthesized new fibrillar materials and collagen fibrils towards the curetted cementum. The results suggested the possibility that this treatment for periodontally involved teeth would provide ideal root surface conditions for the formation of new fibrous attachment.     

Segmentation and root localization for analysis of dental radiographs

During lifetime, teeth are exposed to many effects like abrasion, loss and dental treatments. These effects along with natural shapes of teeth form a unique dental frame which contains useful attributes to be used for human identification. Today, there exist automated dental identification systems which are used by forensics of law departments. These systems need to extract dental structures like teeth or roots prior to further analysis. So far, in several studies, much effort has been paid for this task. However, there still exist core problems like automated detection of region of interest (ROI) and segmentation in panoramic dental radiographs with missing teeth. This study aims to present a tool that can be employed to overcome these issues. Unlike previous works, the proposed methodology takes advantage of discrete wavelet transform for more accurate localization of ROI and polynomial regression to form a smooth border, separating upper and lower jaws even in case of absent teeth. Results indicate that the proposed approach can be effectively used for teeth segmentation and root apex detection.     

太赫兹光谱成像龋齿检测

龋齿是一种广泛存在的慢性传染病,如果不及时采取治疗措施,可能会引发一系列口腔和人体健康问题,因此龋齿的早期筛查和治疗后的恢复跟踪诊疗非常重要.太赫兹电磁波对牙齿拥有较强的穿透性和非电离辐射,使其成为未来龋齿早筛的重要潜在手段之一.本文使用太赫兹时域光谱成像分析仪对含有龋病的牙齿切片进行了二维太赫兹脉冲透射扫描成像.实验结果表明：由于牙齿中不同组织对太赫兹脉冲的响应不同,该技术可有效对牙釉质、牙本质和牙釉质龋进行区分和检测;采用频域成像分析,也可对牙本质龋进行检测.太赫兹谱学成像技术可为龋齿早期筛查提供一种无电离辐射、非接触、高可靠性的新手段.     

Personalized tooth shape estimation from radiograph and cast

Three-dimensional geometric information of teeth is usually needed in pre- and postoperative diagnoses of orthodontic dentistry. The computerized tomography can provide comprehensive 3-D teeth geometries. However, there is still a discussion on computed tomography (CT) as a routine in orthodontic dentistry due to radiation dose. Moreover, the CT is useless when a dentist needs to extract 3-D structures from old archive files with only radiographs and casts, where patient's teeth changed ever since. In this paper, we propose a reconstruction framework for patient-specific teeth based on an integration of 2-D radiographs and digitized casts. The reconstruction is under a template-fitting framework. The shape and orientation of teeth templates are tuned in accordance with patient's radiographs. Specially, the tooth root morphology is controlled by 2-D contours in radiographs. With ray tracing and a contour plane assumption, 2-D root contours in radiographs are projected back to 3-D space, and guide tooth root deformations. Moreover, the template's crown is deformed nonrigidly to fit digitized casts that bear patient's crown details. The system allows 3-D tooth reconstruction with patient-specific geometric details from just casts and 2-D radiographs.     

Relations Between Shape,Materials Properties,and Function in Biological Materials Using Laser Speckle Interferometry: In situ Tooth Deformation

The manner in which stiff biological objects, such as whole bones and teeth, deform under load can provide direct insight into their in vivo functions, while highlighting the relations between their structure and materials properties. A new approach for studying the mechanical functions of such objects, using as an example the crowns of human teeth, is developed. Tooth‐crown deformation under a compressive load is determined in water using laser speckle interferometry. The deformation patterns are analyzed using a novel procedure that reveals the relative magnitudes of 3D displacements of the outer surface. Nanometer‐scale deformations of natural teeth were compared to deformations of identical acrylic replicas, in order to differentiate between contributions of the structure–material properties from contributions of morphology. It is shown that human premolars deform in a manner that is largely controlled by shape; in natural teeth, the enamel cap appears to displace mainly as a rigid body, undergoing moderate deformation. These observations contribute to the understanding of whole‐tooth performance under load. The approach for analyzing the deformation of loaded whole objects is directly applicable to the study of many stiff biological specimens, including comparisons between normal and altered (repaired or genetically modified) bones.     

Development of a magnetic sensing device for tooth displacement under orthodontic forces

We have developed a system for measuring tooth displacement from orthodontic force. Eight small magnetic sensors and a magnet are combined to measure three-dimensional displacement. Sensors, arranged cubically in the three planes of space, are placed in the mouth and fixed to the posterior teeth by a splint. A magnet is placed in the center of the eight sensors and attached to a front tooth that is subjected to orthodontic force. Sensors detect the magnet's movement as target tooth displacement. The system was designed to achieve displacement resolution of 1 microm. The mean percentage of measurement errors was determined to be less than 1% in a 600-cubic-microm volume from calibration. The system was tested clinically on human teeth. Although the oral environment, with high temperature and humidity, was not agreeable with the sensors, this system was stable and accurate enough for quantitative measurement of tooth displacement. The advantage of this system is the ability to detect tooth trajectories by decomposing displacement into translation and rotation and to determine the position of the center of rotation from these parameters.