更改机动车辆号码的常见方法及检验

更改机动车辆车架号码和发动机号码是犯罪分子的惯用伎俩,常用方法有割改法、填改法、添减笔画法、添减阿拉伯数字法和移位法等。发现车辆号码更改的方法有观察车辆驾驶室内仪表盘,观察车辆发动机号码平台,以及牢记各类型车辆的发动机号码和车辆车架号码的字体特征、打印部位、打印方式、倾斜角度等特征,并进行比对。显现变动的车辆号码的方法一般用化学试剂显现。     

对大学生网络交友速度的研究

大学生网络交友的渠道有聊天室、网络游戏、网络论坛等,其中又以网络聊天为主。与传统交友相比,网络聊天交友缺少伦理制约、身份认同,存在着很大的安全隐患、情感盲区。大学生网络交友速度之快,已经没有传统朋友之间的真诚、互信。对此,我们需要加强对大学生网络交友情感的正面引导、网络安全教育,搞好网络心理咨询等。     

Preparation of a low-cost fingerprint powder that harnesses white light to emit long-lived phosphorescence

An inexpensive, commercially available doped strontium aluminate phosphor with long-lived afterglow has been prepared and assessed in the role of a luminescent fingerprint dusting powder. Blue, green, and aqua phosphorescence persisting for ca. 30 s was obtainable from treated fingermarks after charging the powders with the white light (400–700 nm) setting of a forensic light source. Imaging the phosphorescent afterglow enabled the elimination of background emissions encountered during latent fingermark examination. This was demonstrated by visualising fingermarks on substrates that possess inbuilt fluorescent security features and highly patterned substrate backgrounds, without any need for bespoke scientific equipment.