基于粒子群分类器的遥感图像目标识别

设计了一种用于遥感图像目标识别的粒子群分类算法。首先对数据样本预处理,利用粒子群优化算法通过训练数据进行分类规则的提取,根据提取得到的规则对遥感图像的目标进行分类识别。通过对实测遥感图像中飞机和舰船目标的识别实验,验证了此算法对遥感图像目标具有较高的识别率。     

Photoinduced Proton Transfer between Photoacid and pH‐Sensitive Dyes: Influence Factors and Application for Visible‐Light‐Responsive Rewritable Paper

Ink‐free printing based on rewritable paper is an efficient and environmental friendly way to reuse paper, protect resources, and save energy for sustainable development of human society. Among various kinds of rewritable media, light responsive rewritable paper (LRP) is one of the most popular research areas due to its clean and favorable noncontact writing. Visible light is more suitable for LRP for its superior penetration and much less damages to organic molecules than UV light. However, visible‐light‐responsive rewritable paper (VLRP) has only limited successes so far. Herein, a VLRP is newly designed and fabricated based on photoinduced proton transfer (PPT) between photoacid and pH‐sensitive dyes. Success of it is highly benefited from systematical investigation and in‐depth understanding on the key influence factors, such as concentration‐induced undesired isomerization, temperature, humidity, and light intensity, on the PPT and its inverse process. As‐prepared VLRP shows long‐awaited properties, such as, high color contrast and resolution, appropriate legible time of prints, excellent reversibility (>100 cycles), easiness to achieve multicolor prints, and agreeing well with environmental concept of green printing. In addition, study of influence factors on PPT in this work, to some extent, may also help people understand complex photocycle process in biosystem.     

Constructing a novel single-layer white organic light-emitting device through a new sky-blue fluorescent bipolar host

A novel device concept was realized for simple single-layer small-molecule white organic light emitting devices. The single organic active layer here is simply comprised of a newly synthesized sky-blue fluorescent bipolar host (TPASO) and a common orange phosphorescent dopant. Suppressed singlet Föster energy transfer induced by a low-concentration doping and spontaneous high- to low-lying triplet energy transfer, respectively, lead to sky-blue fluorescence from TPASO and orange phosphorescence from the dopant. The resulting two-organic-component device exhibits a low turn-on voltage of 2.4 V, maximum current/power efficiencies up to 11.27 ± 0.02 cd A⁻¹ and 14.15 ± 0.03 lm W⁻¹, and a warm-white CIE coordinate of (0.42, 0.45) at 1000 cd m⁻².     

Comments on "An efficient PML implementation for the ADI-FDTD method"

For original paper see Wang and Teixeira (IEEE Microwave Wireless Comp. Lett., vol.13, p.72-4, 2003 February). In this paper, a more precise way to evaluate the actual performance of the perfectly matched layer (PML) used for the alternating direction implicit finite-difference time-domain (ADI-FDTD) method is presented. It is shown that the intrinsic numerical dispersion error of the ADI-FDTD method must be taken into account when the actual performance of the ADI-PML (as well as the ADI-FDTD method) is evaluated. Most importantly, it is demonstrated that the ADI-PMLs implemented with either the traditional manner or the way proposed in have almost the same level of accuracy when the performance of the ADI-PML is correctly evaluated.     

Nonvolatile flash memory device using Ge nanocrystals embedded in HfAlO high-/spl kappa/tunneling and control oxides: Device fabrication and electrical performance

We fabricated a nonvolatile Flash memory device using Ge nanocrystals (NCs) floating-gate (FG)-embedded in HfAlO high-/spl kappa/ tunneling/control oxides. Process compatibility and memory operation of the device were investigated. Results show that Ge-NC have good thermal stability in the HfAlO matrix as indicated by the negative Gibbs free energy changes for both reactions of GeO/sub 2/+Hf/spl rarr/HfO/sub 2/+Ge and 3GeO/sub 2/+4Al/spl rarr/2Al/sub 2/O/sub 3/+3Ge. This stability implies that the fabricated structure can be compatible with the standard CMOS process with the ability to sustain source-drain activation anneal temperatures. Compared with Si-NC embedded in HfO/sub 2/, Ge-NC embedded in HfAlO can provide more electron traps, thereby enlarging the memory window. It is also shown that this structure can achieve a low programming voltage of 6-7 V for fast programming, a long charge retention time of ten years maintaining a 0.7-V memory window, and good endurance characteristics of up to 10/sup 6/ rewrite cycles. This paper shows that the Ge-NC embedded in HfAlO is a promising candidate for further scaling of FG Flash memory devices.     

三维半导体GaAs量子阱微腔中的腔极化激元

半导体微腔中腔模和激子模耦合形成腔极化激元,三维微腔中由于横向限定腔模和激子模形成离散化的本征模式.本文计算了远离截止近似下,三维半导体微腔中空腔腔模的能量与微腔半径的关系;及腔模和激子模耦合后,三维半导体柱型微腔中具有相同角量子数和径向量子数的两个低阶腔模、重空穴激子模、轻空穴激子模耦合形成的腔极化激元能量随微腔半径变化的情况.结果表明随着微腔半径的减小腔模能量蓝移,腔模与相应的重空穴激子模、轻空穴激子模耦合形成的腔极化激元的三支随着微腔半径的减小存在明显的反交叉行为.随着微腔半径的变化,极化激元的三支所体现的模     

同轴环形螺旋谐振腔设计分析

提出了一种适用于同轴环形放电结构气体激光器的环形螺旋谐振腔,并给出了理论分析。该谐振腔由一螺旋面反射镜和一球面反射镜构成,可充分提取激活区的能量并输出单束激光。该结构易于实现同轴环形放电激活区中的功率萃取。     

世界与中国的石油储产量现状及趋势

总结了2004年世界和中国石油储量、产量和贸易量的特点,预测了未来世界和中国石油供需的发展趋势。     

平圩电厂2号锅炉分隔屏爆管原因分析及其解决措施

安徽淮南平圩发电有限责任公司的2号锅炉是采用美国CE公司技术,由哈尔滨锅炉厂设计制造的我国首批60万千瓦亚临界燃煤锅炉,自2003年7月2日以来,分隔屏左数第4片屏超温爆管,通过计算和试验发现,由于连接第3、4片屏炉外管的阻力大,流量小,并与宽度方向上的热偏差及同屏热偏差,几者叠合,造成3号、4号屏超温严重。通过研究找出了产生超温爆管的原因,并提出了攻关方案,现正在施工中。图9表2     

界面改性剂对天然橡胶/纳米粘土复合材料性能的影响

以4个不同厂家的界面改性剂改性纳米粘土,以乳液共混法制备天然橡胶(NR)/纳米粘土复合材料,研究界面改性剂对复合材料性能的影响。结果表明,不同厂家界面改性剂的理化性能及其改性的纳米粘土制得的复合材料性能差异明显,有的厂家界面改性剂改性的纳米粘土与NR的结合较好,有的厂家界面改性剂改性的纳米粘土制得的复合材料硫化效率较高。