摘要：针对含有执行器非线性的车辆队列控制系统,提出一种固定时间全局预设性能控制(Global prescribed performance control, GPPC)控制方法.首先,设计一种平滑等效变换,在同一框架下解决死区及饱和问题,同时消除执行器非线性固有拐点问题.其次,构造两个新型性能函数,并基于此提出一种全局预设性能控制算法,实现如下目标:1)保证跟踪误差在固定时间内收敛到预定稳态区域;2)消除初始误差必须已知的限制;3)减小误差的超调量.然后,基于上述等效变换及预设性能控制算法,设计一种固定时间滑模队列容错控制方案,实现固定时间单车稳定及队列稳定.最后,通过MATLAB仿真实验,验证了所提算法的有效性.

摘要：Fast migration and efficient spatial separation of photogenerated charges in photocatalytic materials are indispensable to efficient solar water splitting ***,we construct a three-phase heterostructure of CdS/PbTiO_(3)/TiO_(2)by selectively depositing CdS and TiO_(2)at oppositely poled crystal facets of PbTiO_(3)using single-domain ferroelectric PbTiO_(3).The heterostructure has matching band edge alignments and strong interfacial connections at different *** heterostructure combines the interfacial electrical and ferroelectric fields because of their peculiar microstructures,which provide a strong driving force throughout the whole bulk to separate photogenerated *** two orders of magnitude improvement of visible-light-driven photocatalytic H_(2) production has been realized in CdS/PbTiO_(3)/TiO_(2)compared with bare PbTiO_(3)/TiO_(2),showing the efficiency of charge separation in the *** idea of combining ferroelectrics with potential light capture semiconductor provides a paradigm to accurately design charge migration pathways,bringing a step closer to efficient solar water splitting.

摘要：Semiconductor heterostructures mediated by electrical conductors are very promising for Z-scheme photocatalytic water *** contrast to conventional particulate heterostructures,alternate TiO_(2)and Cu_(2)O film stripes patterned parallel on a fluorine-doped tin oxide(FTO) conductive substrate was fabricated as a model film photocatalyst to study the characteristics of the photogenerated charge transfer *** Z-scheme transfer process with an effective transport distance of up to 5 μm occurs only in regions distant from the TiO_(2)/Cu_(2)O strip edges through the FTO substrate from the *** contrast,the transfer of charge around their contact regions follows the conventional transfer process through the TiO_(2)/Cu_(2)O strip *** results indicate that the Z-scheme transfer process occurring in such a large region dominates the charge transfer processes in the TiO_(2)/FTO/Cu_(2)O pattern film ***,unlike the single component film,which is inactive for photocatalytic overall water splitting,the modified TiO_(2)/Cu_(2)O pattern film can induce photocatalytic overall water splitting at a stoichiometric H_(2)/O_(2) ratio close to 2:*** findings have significant implications in designing efficient heterostructures by employing a Z-scheme charge transfer process.

摘要：为培养土木工程类学生防灾减灾设计能力,本文以《基于保持建筑正常使用功能的抗震技术导则》(以下简称《导则》)为核心内容,提出建筑物在遭受设防地震时满足正常使用要求,并根据使用功能及损坏后果提出Ⅰ、Ⅱ类建筑性能目标。以预期抗震韧性目标为导向,提出一种面向两区八类建筑的“三水准设防、两阶段设计”策略,以实现《导则》对Ⅰ、Ⅱ类建筑进行减隔震设计时正常使用要求,提高震后建筑维持和恢复使用功能的能力。选取某医技楼和学校作为Ⅰ类和Ⅱ类建筑的典型算例,以震后修复费用、修复时间和人员伤亡指标提出预期韧性目标,并对其按照韧性设防策略进行隔震与减震设计。基于弹塑性时程分析结果采用SAUSG-RES提取工程需求参数进行韧性等级评定。结果表明,两区八类建筑采用韧性设防策略后,结构在遭受设防地震时满足正常使用要求,经过简单修复后可恢复使用功能,达到韧性一星等级;在遭受罕遇地震后经过适度修复可恢复使用功能,达到高韧性等级。韧性设防策略不仅完善了传统抗震设防的不足,而且衔接《导则》要求与工程设计习惯,为抗震设计课程高阶性改革提供了参考思路。

摘要：为确定高等级立体复合通道可变信息标志的安全布设间距,基于狮子洋通道设计方案开展了驾驶模拟试验。试验选取了相邻路段车速差值、运行车速与设计车速差值、车速降低系数为分析指标,共采集30名驾驶员的试验数据。结果显示,不同布设间距会影响驾驶员对行车速度的决策,从而对行车安全性产生影响,其中2 km间距方案对速度影响相对平顺,安全性较高。

摘要：为能够准确、快速识别网络攻击者,提出一种基于黑客画像的网络攻击者识别方法。构建将稀疏自编码器和贝叶斯神经网络相结合的SAE-BNN模型,检测不同攻击类型的恶意流量;针对不同的恶意流量,通过提取黑客属性特征、流量特征、时间特征和相似性特征,与事先建立的黑客画像库中的黑客画像进行匹配。如果与某个黑客画像完全匹配,则由此确定该黑客的身份。当不能与黑客画像库中的任何黑客画像进行匹配时,将该黑客的特征作为标签,构建新的黑客画像,并更新画像库。实验结果表明,提出的异常流量识别方法在精度、召回率、F1值和准确率上均有提升。基于黑客画像的黑客识别算法与常规方法相比,极大提高了识别效率。

摘要：Common solar-driven photoelectrochemical(PEC) cells for water splitting were designed by using semiconducting photoactive materials as working photoelectrodes to capture sunlight. Due to the thermodynamic requirement of 1.23 eV and kinetic energy loss of about 0.6 eV, a photo-voltage of 1.8 V produced by PEC cells is generally required for spontaneous water splitting. Therefore, the minimum bandgap of1.8 eV is demanded for photoactive materials in single-photoelectrode PEC cells, and the bandgap of about 1 eV for back photoactive materials is appropriate in tandem PEC cells. All these PEC cells cannot effectively utilize the infrared light from 1250 to 2500 nm. In order to realize the full spectrum utilization of solar light, here, we develop a solar-driven PEC water splitting system integrated with a thermoelectric device. The key feature of this system is that the thermoelectric device produces a voltage as an additional bias for the PEC system by using the temperature difference between the incident infrared-light heated aqueous electrolyte in the PEC cell as the hot source and unirradiated external water as the cold source. Compared to a reference PEC system without the thermoelectric device, this system has a significantly improved overall water splitting activity of 1.6 times and may provide a strategy for accelerating the application of full spectrum solar light-driven PEC cells for hydrogen production.

摘要：为了提高巡检效率和避障精度,提出了基于机器学习的机器人自动巡检系统。根据机器人巡检电机驱动器的内部结构,给出电机驱动的技术参数,利用巡检电机驱动器的外部接口,将巡检电机驱动器与其他硬件连接,通过引入一个调理电路,调节电机驱动器的输出电压,设计了机器人自动巡检电路;软件设计中,规划了机器人巡检路径,利用机器学习算法推算出机器人的巡检轨迹,计算出机器人巡检过程中方位的置信度,结合机器人自动巡检算法的设计,实现了机器人的自动巡检。实验结果表明,所提系统在机器人自动巡检中,可以将巡检效率和避障精度分别控制在83%和85%以上。

摘要：为研究流固耦合对LNG储罐外罐的地震响应问题,采用振动台试验和数值仿真相结合方法对不同地震波下不同液体高度的LNG储罐进行震动分析。试验结果表明:地震会改变罐体加速度和位移的分布情况,不同地震波和不同液体高度对位移和加速度的放大效应有着不同的影响,在El Centro波、Taft波和SHM2波作用下,流体振荡产生的减震作用和流体压力产生的附加惯性作用能够减小储罐中部的位移,但对加速度有所放大。利用时程分析法对5000m^(3)LNG储罐的位移和环向应力进行地震模拟分析,结果表明:储罐的环向应力呈现出中间大两头小的走势,在罐高的1/4h、1/2h和3/4h上出现极值;位移沿罐高度方向先增加后减少,峰值出现在1/4h、1/3h、1/2h和3/4h处。因此在LNG储罐抗震设计时,应考虑流固耦合效应对结构的影响,在1/4h、1/3h、1/2h和3/4h处的薄弱位置,宜采用增加壁厚、设置阻尼器和钢筋加密等措施增强结构的可靠性和安全性。

摘要：中小学核心素养变革要求师范院校培养能够解决真实教学问题的职前教师。以两难或多难问题为核心的教学困境是课堂生活的组成部分,对教学困境的决策凸显教育硕士研究生的教学能力。困境决策视角的教育硕士研究生教学能力包括诊断教学困境类型并设计教学目标的能力、把握教学困境的学科特殊性以整合教学内容的能力、在动态困境中做出即时性教学决策的能力、对教学困境决策进行反思的“元决策”能力。借助教学困境决策提高教育硕士研究生的教学能力,高校要在培养方案中强化研究生的问题解决能力培养,以“创中学”为主线整合三类学习方式,校地协同丰富研究生的教学困境决策,指导研究生对教学困境决策进行深度反思,以提高研究生的培养质量。