基于人工智能的机器人折弯机滑块行程研究

针对金属板料折弯工艺和更高精度的要求,提出基于人工智能神经网络的机器人折弯新技术。对机器人弯折工艺进行特征参数分析及提取,并建立改进算法的BP神经网络模型;比较了不同机器人折弯训练函数下的性能,建立更加有效的神经网络训练函数。通过经验实测值与改进算法的BP神经网络预测值对比,验证了所确定的机器人折弯的改进BP神经网络能够更加精准确定折弯工艺过程中所需的滑块行程,提高了折弯工艺精度。     

对高校体育课堂教学心理变化之研究

体育课堂教学对大学生心理影响不纯粹在课堂“封闭交流”中,按逻辑来推理,按自身法则发展,它是取决于社会背景和“周边环境”。即与社会心理因素相匹美,相适应。他的整体特征是个体心理因素间的内在协调,自给程度以及个体心理与外在因素之间相容程度的合取。所以,体育课堂教学对大学生心理各因素之间的影响不是单相的,线性的,而是多维网状的,且可以调整的。     

A quantitative evaluation of the high elbow technique in front crawl

Many coaches often instruct swimmers to keep the elbow in a high position (high elbow position) during early phase of the underwater stroke motion (pull phase) in front crawl, however, the high elbow position has never been quantitatively evaluated. The aims of this study were (1) to quantitatively evaluate the “high elbow” position, (2) to clarify the relationship between the high elbow position and required upper limb configuration and (3) to examine the efficacy of high elbow position on the resultant swimming velocity. Sixteen highly skilled and 6 novice male swimmers performed 25 m front crawl with maximal effort and their 3-dimensional arm stroke motion was captured at 60 Hz. An attempt was made to develop a new index to evaluate the high elbow position (I_he: high elbow index) using 3-dimensional coordinates of the shoulder, elbow and wrist joints. I_he of skilled swimmers moderately correlated with the average shoulder internal rotation angle (r = ?0.652, P < 0.01) and swimming velocity (r = ?0.683, P < 0.01) during the pull phase. These results indicate that I_he is a useful index for evaluating high elbow arm stroke technique during the pull phase in front crawl.     

Room-temperature coherent manipulation of single-spin qubits in silicon carbide with a high readout contrast

Spin defects in silicon carbide (SiC) with mature wafer-scale fabrication and micro/nano-processing technologies have recently drawn considerable attention. Although room-temperature single-spin manipulation of colour centres in SiC has been demonstrated, the typically detected contrast is less than 2, and the photon count rate is also low. Here, we present the coherent manipulation of single divacancy spins in 4H-SiC with a high readout contrast () and a high photon count rate (150 kilo counts per second) under ambient conditions, which are competitive with the nitrogen-vacancy centres in diamond. Coupling between a single defect spin and a nearby nuclear spin is also observed. We further provide a theoretical explanation for the high readout contrast by analysing the defect levels and decay paths. Since the high readout contrast is of utmost importance in many applications of quantum technologies, this work might open a new territory for SiC-based quantum devices with many advanced properties of the host material.     

国库集中支付制度在高校实施中的问题及完善措施

分析了国库集中支付制度在高校实施中与高校现行的经济运行、财务管理及会计核算体系产生的矛盾。表现为独立法人地位和预算资金的严格限制相矛盾、银校合作受到制约、支付方式与现行系统存在冲突。在强化预算管理、转变会计职能、推行政府采购、开通远程查报账系统和完善内外监控制度等几大方面提出了完善会计集中核算的对策建议。     

基于FPGA的高速浮点FFT/IFFT处理器设计与实现

设计一种基于FPGA的改进的并行FFT/IFFT蝶形运算结构.该结构采用按时间抽选的FFT基-2蝶形算法对IEEE单精度浮点数构成的复数进行8路并行处理.利用Xilinx ISE 13.1软件完成FFT/IFFT处理器的设计, 并在Virtex6硬件平台上进行验证.结果表明, 利用这种8路并行结构设计的FFT/IFFT处理器可在合理利用硬件资源的同时提高运算速度及精度.     

我国上市公司财务预警方法探讨

上市公司建立财务预警机制,不仅可以避免或减少财务危机对企业的破坏,而且可以帮助投资者、银行等相关利益者避免风险,促使证管当局加强监管,进而推动我国资本市场健康有序地发展。财务预警方法主要是通过建立财务预警模型来进行的,具体可分为单变量预测模型法和多变量预测模型法两类。虽然两类方法使用了不同的研究方式,具有不同的侧重点,但两者可以同时运用,相互补充,以提高预测的准确性。     

人行走速度规律的实验研究

阐述了人的运动特性,其步行速度具有波动性,用正弦曲线拟合,可得到很高的置信度,并得出结论：单脚支撑转换成以脚支撑时人的躯体速度最快,双脚支撑转换成单脚支撑时速度最慢。     

Epitaxial growth of Ga x In1−x As film by RF sputtering and physical properties of the films

Single crystal Ga _x In_1−x As films have grown up on GaAs(100) substrate at 375°C and on InP(100) substrate at 390°C, respectively, by the method of rf-sputtering with using undoped GalnAs polycrystal as target. However, on Si(100) or Si(111) substrates at 260–390°C, even at 465°C, only polycrystalline films were obtained. In addition, the structure, composition, electrical characteristic and optical properties of the Ga _x In_1−x As films were investigated using X-ray diffraction (XRD), reflection of high energy electron diffraction (RHEED), energy dispersion analyzer of X-ray (EDAX), Hall measurements and spectroscopic ellipsometry.     

无线寻呼系统中频率合成器的设计

为得到频率稳定度高,频谱纯净的特定频率信号,采用单片机Ｉｎｔｅｌ８０３１对大规模集成锁相环频率合成器ＭＣ１４５１２进行控制,可获得合乎质量要求的频率信号,且设计出的频率合成器具有可靠性高,成本低,体积小,使用灵活方便的特点,文中通过一个具体实例从技术指标,方案选择,工作原理及实施等几方面介绍了这种频率合成器的设计方法。