咬合面和支架整体铸造修复低间隙后牙缺失的应用研究

方法：应用咬合面和支架整体铸造修复97例低间隙后牙缺失，并以成品丝材制作的修复体为对照组，并对修复效果随访。随访6—30个月：咬合面和支架整体铸造修复成功率94．8％，优于对照组73．6％。     

Portable high‐resolution automated 3D imaging for footwear and tire impression capture

The forensic science community raised the need for improved evidence recognition, collection, and visualization analytical instrumentation for field and laboratory use. While the 3D optical techniques for imaging static objects have been extensively studied, there is still a major gap between current knowledge and collecting high‐quality footwear and tire impression evidence. Among optical means for 3D imaging, digital fringe projection (DFP) techniques reconstruct 3D shape from phase information, achieving camera‐pixel spatial resolution. This paper presents a high‐resolution 3D imaging technology using DFP techniques dedicated to footwear and tire impression capture. We developed fully automated software algorithms and a graphical user interface (GUI) that allow anyone without training to operate for high‐quality 3D data capture. We performed accuracy evaluations and comparisons comparing with the commercial high‐end 3D scanner and carried out qualitative tests for various impressions comparing with the current practices. Overall, our technology achieves similar levels of accuracy and resolution with a high‐end commercially available 3D scanner, while having the merits of being (1) more affordable; (2) much easier to operate; and (3) more robust. Compared with the current practice of casting, our technology demonstrates its superiority because it (1) is non‐destructive; (2) collects more evidence detail than casts, especially when an impression is fragile; (3) requires less time and money to collect each piece of evidence; and (4) results in a digital file that can easily be shared with other examiners.     

机车闸瓦熔渣导致的护坡起火现场勘查分析

青藏铁路是进出藏运输大动脉,客运和货运量巨大,具有极高的战略地位,铁路护坡起火严重危害青藏铁路行车安全。本文通过对青藏铁路格拉段沿线发生的5例起火事件的现场勘查,排除了人为因素导致起火的可能性。结合事发地地理环境以及列车闸瓦特性,明确发生的火灾事件均由机车闸瓦熔渣飞溅点燃护坡杂草导致。本文为此类事件的调查取证和事件定性提供了参考,并为防范青藏铁路类似事件的发生提出了预防措施。     

硫磺制模法提取雪地足迹的优势

目的比较硫磺制模法与石膏制模法提取雪地足迹的效果。方法分别用两种制模法实验,观察比较操作流程、制模时间、细节特征反映等方面。结果硫磺制模法在雪地足迹提取的速度、细节特征反映等方面优于石膏制模法。结论与传统的石膏制模法相比,硫磺制模法更加迅速、简便,在细节特征的反映更加清晰。     

几类特殊客体上指纹的树脂提取法

在犯罪现场上经常会遗留犯罪嫌疑人的指纹,遗留指纹的客体种类繁多,有几类特殊客体上的指纹较难提取,如粗糙客体、人体皮肤、曲面客体等。文章通过实验研究发现,磁性粉末刷显法与树脂制模法配合使用,可以很好地提取这些特殊客体上的指纹,树脂制模提取指纹的方法为指纹的提取提供了一条新途径。     

Evaluation and comparison of the electrostatic dust print lifter and the electrostatic detection apparatus on the development of footwear impressions on paper

The Electrostatic Dust Print Lifter (EDPL) and the Electrostatic Detection Apparatus(2) (ESDA(2)) were compared to determine if both processes could be used to develop footwear impressions of the same or similar quality and in what order they should be used to develop the highest quality footwear impression. The sensitivity of each technique was also evaluated. The quality of the footwear impressions developed was determined by comparing 25 individual characteristics present on the known shoe to the footwear impressions developed using each technique. The footwear impressions were made by stepping on paper placed over several different surfaces, which included: linoleum, industrial Berber carpet, nylon carpet placed over a (3/8)-in. pad, ceramic tile, cardboard, 1-in. foam, 4-in. foam, cement, asphalt, grass, and mulch. Each of the papers placed on these surfaces was developed using the EDPL before the ESDA(2) and vice versa. The sensitivity test for the ESDA(2) was conducted by processing 10 sheets of stacked paper that were stepped on with the known shoe, beginning with the top sheet. The sensitivity test for the EDPL was conducted by processing 10 sheets of paper stepped on with the known shoe in succession. This study determined the footwear impressions developed using the EDPL were of better comparative value than impressions developed with the ESDA(2). On average, 72.4% of the individual characteristics from the known impression were identified on images developed when the EDPL was used first compared with an average of 38.9% when the ESDA(2) was used first. Therefore, if only one technique is used, the EDPL should be chosen. The sensitivity test determined the ESDA(2) develops high-quality footwear impressions on only the top sheet of paper. No footwear impressions were developed on any sheets under the top sheet of paper. The sensitivity test also determined the EDPL results increase in quality as the amount of dust residue decreases on the surface.     

A new method for casting three-dimensional shoeprints and tire marks with dental stone

Dental stone is used as the major material for recovering three-dimensional shoeprints and tire tracks from crime scenes. The procedure for using dental stone sparsely changed over the years. There are two common methods for mixing dental stone: (i) a premeasured amount of dental stone is put in a zip-lock bag to which water is added, and (ii) the water and dental stone are mixed in a bucket. We suggest a novel rapid and efficient method of mixing dental stone and water in a bottle. These methods were compared at equal conditions. The parameters measured were the number of air bubbles, the strength of the cast, the ease of use, and the sharpness and quality of the accidental characteristics present in the cast. The proposed bottle method has the advantages of both the bucket and the zip-lock methods hence it combines strength, sharpness, high quality, and ease of use.     

A Comparison of Various Fixatives for Casting Footwear Impressions in Sand at Crime Scenes

Footwear examination can provide an important link between the crime scene and the suspect. Casts have been taken from snow, soil, and sand substrates to assist with the examination and to accurately depict the impression. However, there has been some discrepancy on what kind of fixative, if any, should be used with impressions present in sand. This study tested four different fixatives on three sandy substrates. Eight gross characteristics were added to a boot sole, and thirty sand impressions were created in each substrate. Except for one control set that remained untreated, the impressions were treated with a fixative agent before casting. The ninety shoe casts were examined by a qualified footwear examiner and scored based on his ability to see the eight characteristics. The results indicated that pump‐action hairspray was the most successful on play and construction sand, while beach sand impressions without any fixative scored highest.     

判别分析法在鞋底磨损特征检验中的应用

目的从统计学角度论证同一人的鞋底磨损特征具有相对稳定性。方法对50名实验对象（同质人群）的穿鞋足迹中的鞋底磨损特征进行量化测量,并对测量结果用判别分析的方法进行处理。结果不同人的鞋底磨损特征具有差异性,并且可用于不同人的鉴别。为利用鞋底磨损特征进行个人识别提供了理论基础。     

双峰驼肾动脉血管分布的铸型观察

运用管道铸型技术以及扫描电镜技术对双峰驼肾动脉血管进行了系统观察。结果显示,双峰驼肾动脉在入肾门前约4~8 cm处分为背干和腹干,入肾后在肾窦内相继形成肾段动脉。左右两肾段动脉的分支分布各有特点,各段动脉分支延伸至肾的皮髓交界处,形成弓形动脉;弓形动脉是叶间动脉的延续,并不与肾表面相平行;肾血管球以及出、入球微动脉因分布区域的不同,形态结构也不尽一致。表明,双峰驼肾各段动脉分布的规律性强,段动脉分支之间没有吻合支存在;肾各部位的血管球随分布区域的不同,其形态结构也呈现一定的变化。