无线传感器网络多sink路由技术研究*

在介绍无线传感器网络路由协议的独有特点后,给出了传感器网络多sink路由协议的分类方法,然后着重分析了当前较为有代表性的多sink路由协议,在协议特点及其应用范围方面进行了研究与比较。最后,总结了多sink路由协议的研究的关键点及其发展趋势。     

高职软件专业人才培养的探索与实践——以江苏商贸职业学院移动互联方向建设为例

结合江苏商贸职业学院软件专业的建设情况,分析移动互联网的现状与发展趋势,结合高职院校软件专业的发展现状,提出开设移动互联网方向的必要性,提出从课程体系和实训体系改革的思路与举措,创新软件人才培养的模式,从而为企业培养移动互联网高技能人才。     

基于PLC的蓄电池组均衡充电系统设计

针对目前蓄电池组充电所存在的不均衡问题,设计了一种新型的均衡充电控制系统,本系统既能保证每个单体蓄电池均能充满电,又能保证整组蓄电池不会发生过充电现象,克服了电池不一致性对电池使用寿命造成的不良影响,提高了蓄电池组容量的有效利用率。     

基于改进3D UNet的前列腺MR图像分割

针对前列腺磁共振 (magnetic resonance, MR)图像边缘模糊、对比度较低,灰度值分布不均衡而导致分割精度较差的问题,提出了一种结合双路径注意力(dual path attention,DPA) 和多尺度特征聚合(multi-scale feature aggregation,MFA) 模块的改进3D UNet网络模型。首先,对数据集进行重采样和裁剪处理以适应模型输入。然后,在3D UNet网络的编码器各层引入DPA 并添加残差连接,加强特征的 编码能力。同时,在网络解码器中加入MFA模块,以充分利用空间上下文信息,增强语义信息。最后,在公开数据集PROMISE12上进行验证,所提出的模型的Dice系数为89.90%,Hausdorff 距离为9.37 mm。相比较于其他模型,所提出模型的分割结果更优,且参数量和运算量更少。     

Analysis of layer splitting in x and z-cut KTiOPO4 implanted by H+ ions

H⁺ ions with various fluences are implanted into x and z-cut KTP crystals to achieve KTP film. Post-implantation annealing under different temperature is imposed on the samples to induce layer splitting and surface morphology modification. Layer exfoliation is observed in freestanding z-cut samples. Layer splitting is obtained using bonding method in x-cut sample implanted with 117 keV H⁺ ions at ion fluence of 6 × 10¹⁶ ions/cm². Optical microscopy, scanning electron microscope and atomic force microscopy are used to observe splitting phenomenon. Rutherford backscattering spectroscopy/channeling method is employed to measure lattice damage and to investigate the relationship between implantation-induced defects and layer splitting.     

大数据时代的设计

目的对大数据时代的设计特征进行分析,探讨大数据背景下设计发展的方向。方法以大数据时代为背景,从设计思维方法、设计思路、设计范畴3个方面进行分析,研究大数据时代设计特征,探讨和传统设计的差异。结论大数据时代设计思维已经由传统注重因果关系转变为注重相关关系;设计不再仅仅依靠传统经验,而更注重大数据分析与应用;大数据时代正在打破传统设计和其他学科之间的篱笆,出现多学科交叉与综合的特点,这种趋势将会成为未来设计的发展方向。     

基于差分演化算法的大规模包匹配研究

在差分演化算法与传统包匹配算法基础上,提出一种改进包匹配算法。该算法包匹配的时间性能与规则数目存在弱相关性,可处理多维和大规模规则库的包匹配问题。数值分析与实验结果表明,与基于Trie类算法相比,该算法能使数据包有效地进行线速转发,改善包匹配性能。     

Interplay between random laser performance and self-frequency conversions in NdxY1.00−xAl3(BO3)4 nanocrystals powders

Random Laser emission at 1.06 μm, self-second-harmonic generation at 0.53 μm and self-sum-frequency generation at 0.46 μm were investigated in Nd_xY_1.00−xAl₃(BO₃)₄ nanocrystalline powders, for 0.05 ⩽ x ⩽ 1.00, excited by a pulsed laser operating at 808 nm, focusing on the interplay between the RL performance and the second-order nonlinear processes. The RL performance, characterized by a figure-of-merit relating the laser slope efficiency and the excitation pulse energy threshold, improved as x increased up to 1.00 while the efficiency of the self-frequency conversion processes reduced for increasing x because of distortions introduced in the crystalline structure of the grains. The RL wavelength was also dependent on the Nd³⁺ concentration and presented a redshift from 1061.9 nm to 1063.5 nm for increasing values of x.     

Colour shift and mechanism investigation on the PMMA diffuser used in LED-based luminaires

PMMA material is widely used in LED-based luminaires due to several advantages such as excellent optical transparency, durability against radiation, surface hardness (scratch free), rigidity and strength and can be completely recycled. However, few studies have been reported on the colour shift and failure mechanisms caused by this type of material. This paper experimentally investigated PMMA materials with different aging conditions. The following conclusions could be drawn. (1) Discolouration was not observed for any sample subjected to aging of 85 °C for 5000 h, or with additional blue light irradiation for 5000 h, or with additional humidity of 85%RH for 5000 h, or even with aging of 100 °C for 3000 h. (2) The specimen subjected to aging of 150 °C for 360 h has a surface discoloration and has a significant wavelength dependent degradation in the transmission spectrum caused by oxidation. The specimen with aging of 100 °C for 3000 h has a less oxidation, although no significant transmission spectrum reduction was observed. (3) Using such aged specimen as a diffuser mounted on a LED-based luminaire, the radiant flux peak intensity in the blue light area has a more severe reduction than that in the yellow light area, which results in a reduction of the radiant flux intensity ratio of blue light to yellow light and hence induces the colour shift to yellow. The colour shift investigated is 0.005, very close to the general failure criterion of 0.007, while the lumen decay is 10.2%, far less than the failure criterion of 30%.     

AUTO CAD在建筑力学计算中的应用研究

对AUTO CAD在建筑力学中几个参数的求解进行了总结,并以悬挑脚手架的力学计算为例,采用AUTO CAD精确计算了其多项参数,证实了此方法在建筑力学计算中的简单实用效果,解决了力学分析计算繁琐的问题。