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81.
Photoshop是由Adobe公司开发的专业平面设计软件,具有强大的图像设计及处理功能,本文主要介绍如何利用中文Photoshop CS中的工具及菜单指令制作心形相框。 相似文献
82.
83.
Li Shibao Wang Mingyu Wang Xiaoli Li Chen Liu Jianhang Cui Xuerong 《Wireless Networks》2022,28(6):2519-2531
Wireless Networks - In the unmanned ship networking scenario, the position of the unmanned ship changes continuously, leading to the result that the desired transmitters and the interference... 相似文献
84.
Cui Ying Guo Dongyan Shao Yanyan Wang Zhenhua Shen Chunhua Zhang Liyan Chen Shengyong 《International Journal of Computer Vision》2022,130(2):550-566
International Journal of Computer Vision - Visual tracking of generic objects is one of the fundamental but challenging problems in computer vision. Here, we propose a novel fully convolutional... 相似文献
85.
The issues of hydrogen generation and storage have hindered the widespread use and commercialization of hydrogen fuel cell vehicles.It is thus highly attractive,but the design and development of highly active non-noble-metal catalysts for on-demand hydrogen release from alkaline NaBH4 solution under mild conditions remains a key challenge.Herein,we describe the use of CoP nanowire array integrated on a Ti mesh (CoP NA/Ti) as a three-dimensional (3D) monolithic catalyst for efficient hydrolytic dehydrogenation of NaBH4 in basic solutions.The CoP NA/Ti works as an on/off switch for on-demand hydrogen generation at a rate of 6,500 mL/(min.g) and a low activation energy of 41 kJ/mol.It is highly robust for repeated usage after recycling,without sacrificing catalytic performance.Remarkably,this catalyst also performs efficiently for the hydrolysis of NH3BH3. 相似文献
86.
An experimental investigation of the homogenization treatment of 2091 Al–Li alloy in the presence of an electric field, has revealed the phenomena of reduced volume fraction, small size, spherical shape and random distribution of second-phase particles, which bring about an increase in ductility. The results show that the dissolution of second-phase particles is promoted by means of the vacancy mechanism, because of the larger diffusion coefficient of solute atoms than the vacancy–solute complexes at the beginning of the homogenization treatment. By increasing the homogenization time and applying an electric field, the diffusion coefficient of vacancy-solute complexes is raised, whereas that of solute atoms is reduced, because of the decreased potential energy of the second phase at grain boundaries. Therefore, the non-equilibrium segregation of magnesium and copper elements is generated near the surface of the ingot by a complex mechanism. An experimental study of the solution treatment under an electric field, revealed that the lithium non-equilibrium segregation is induced at grain boundaries responsible for the precipitates. © 1998 Chapman & Hall 相似文献
87.
Molecular dynamic model of nanofluid between flat plates under shear flow conditions was built. The nanofluid model consisted
of 12 spherical copper nanoparticles with each particle diameter of 4 nm and argon atoms as base liquid. The Lennard–Jones
(LJ) potential function was adopted to deal with the interactions between atoms. Thus, the motion states of nanoparticles
during the process of flowing were obtained and the flow behaviors of nanofluid between flat plates at different moments could
be analyzed. The simulation results showed that an absorption layer of argon atoms existed surrounding each nanoparticle and
would accompany with the particle to move. The absorption layer contributed little to the flow of nanoparticles but much to
the heat transferring in nanofluids. Another phenomenon observed during shear flowing process was that the nanoparticles would
vibrate and rotate besides main flowing with liquid argon and these micro-motions could strengthen partial flowing in nanofluids. 相似文献
88.
同址干扰是车载、舰载、机载无线电通信中面临的一个重要问题,针对同址干扰对复杂通信系统的影响提出了一种有效的测试和分析方法;首先对车载电台的各种天线进行了耦合度测试,从实验和仿真两方面阐述了同址干扰的严重程度,为进一步定量分析同址干扰的影响,构建了有线测试平台;在需求分析基础上,详细介绍了平台的组成,并以短波、超短波电台为对象,通过大量现场实验,深入分析了误码率,同址工作电台的频率间隔和功率之间的相互关系;研究表明,同址干扰的定量分析是设计车载通信系统,合理分配电台工作参数的关键环节。 相似文献
89.
车载平台的变形对光电经纬仪测角精度将产生一定的影响,使车载经纬仪难以达到高精度测量的目的;为了提高车载经纬仪静态测角精度,提出了基于查找表的静态测角误差事后补偿技术;首先,推导出车载经纬仪的静态测角误差修正模型。然后,利用安放在经纬仪垂直轴上的倾角传感器采集车载平台变形特征值;最后,构建映射函数,建立输入值和输出值之间的查找关系,即高精度的查找表;实验数据分析结果表明:该方法能有效补偿因为车载平台变形而带来的静态测角误差,使方位测角精度提高46″,高低测角精度提高20″;为实现车载经纬仪高精度测量提供了理论依据和技术支持。 相似文献
90.
研究了GMSK调制方式在跳频通信应用,结合跳频通信中常见VHF跳频电台的工作模式,在Simulink下模拟仿真了基于FH- GMSK调制的VHF跳频电台发射和接收模块,给出了在不同信噪比下的误码率;研究了VHF跳频电台存在的敌意干扰,包括跟踪干扰和阻塞干扰,建立了上述干扰的模型,并在Simulink下构建了干扰模块,同时给出了相关的仿真频谱图,为进一步研究干扰识别中频谱特征提取打下了基础. 相似文献