摘要：This paper aims at probing the flow characteristics of a jet in supersonic crossflow(JISC)by installing a vortex generator(VG)upstream of the jet *** planar laser scattering(NPLS)and stereo-particle image velocimetry(SPIV)technologies were employed to observe the flowfield,and three cases were designed for ***0 stands for JISC without passive *** CASE1 and CASE2,VG is installed at 20 mm and 80 mm upstream away from the jet orifice,*** flow structures show that two flow modes exist when the VG wake interacts with the *** CASE1,vortices are induced from both sides of the jet plume because of the VG *** leads to a complex streamwise vortex *** and lateral diffusion are *** CASE2,intermittent large-scale eddies in the VG wake cause large streamwise vortices at the windward side of the *** penetration depth is also enhanced while the lateral diffusion is *** addition,experimental results show that the penetration depth is approximately 8.5%higher in CASE1 than that in CASE0,and the lateral diffusion is larger by about 17.0%.In CASE2,the penetration is increased by about 26.2%,while the lateral diffusion is enhanced by just 0.5%.

摘要：以经济效益为目标函数,软土地基路基工后沉降、沉降速率双控制指标为约束条件,建立了砂井联合超载预压处理软土地基的优化设计模型。通过一实例,采用遗传算法对控制工后沉降的3个主要设计参数:砂井间距、超载量和预压时间进行了优化求解。按优化的参数结果表明,通常情况下铺轨时加固区主固结沉降已完成,地基的工后主固结沉降大小主要取决于砂井底部的受压土层,控制的主要参数为超载量和预压时间,同时表明了作者所采用方法的有效性。

摘要：高速铁路对路基的工后沉降提出了严格的要求 ,而现有的软土地基沉降计算方法难以满足设计要求 .通过对软土厚度 10m、路基长度 6 5m和高度 4 .5m的路基原位试验 ,分析了塑料排水板处理软土、堆载预压对地基工后沉降的影响 .

摘要：The erosion shape and the law of development of debris flow sabo dam downstream is a weak part in the study on debris flow erosion. The shape and development of scour pit have an important effect on the stability and safety of debris flow sabo dam, which determines the foundational depth of the dam and the design of protective measures downstream. Study on the scouring law of sabo dam downstream can evaluate the erosion range and reasonably arrange auxiliary protective engineering. Therefore, a series of flume experiments are carried out including different debris flow characteristics （density is varying from 1.5 t/m3 to 2.1 t/m~） and different gully longitudinal slopes. The result shows that the scour pit appears as an oval shape in a plane and deep in the middle while superficial at the ends in the longitudinal section, the position of the maximum depth point moves towards downstream with an increase of flume slope angle. The maximum depth of scour pit is mainly affected by the longitudinal slope of gully, density of debris flow, and the characteristics of gully composition （particle size and the viscosity of soil）. The result also indicates that the viscosity of soil will weaken the erosion extent. The interior slopes of scour pit are different between the upstream and the downstream, and the downstream slope is smaller than the upper one. For the viscous and non-viscous sands with the same distribution of gradation, the interior slope of non- viscous sand is smaller than the viscous *** to tbe regression analysis on the experimental data, the quantitative relationship between the interior slope of scour pit, slope of repose under water and the longitudinal slope of gully is established and it can be used to calculate the interior slope of scour pit. The results can provide the basis for the parameter design of the debris flow control engineering foundation.

摘要：In this weigh-in-motion(WIM)research,a novel fiber Bragg grating(FBG)-based weigh-in-motion(WIM)system was *** design derived from the idea using in-service bridge abutments as the weigh *** bridge beam was replaced by a piece of steel plate which supports the weight of the traveling *** weights would be finally transferred into the tubes where four FBGs were attached and could record the weight-induced strains by shifting their Bragg *** system identification algorithm based on parameters estimation was *** 40-ton load had been applied on the system and the experimental results showed a good repeatability and *** system resolution had been achieved as low as 10 *** with other designs of fiber-optic WIM systems,this design is easy and reliable.

摘要：提出了一种利用0.8μm标准CMOS工艺实现的多传感器数据融合系统.分析了该系统的工作原理,讨论了模拟集成电路子系统的模块设计和组成,论证了系统组成中电路部分的设计细节.通过电路仿真验证了这种数据融合系统的可行性,给出了在0.8μm标准CMOS工艺环境下的系统设计版图,从而可以进行流片操作.

摘要：根据水声通信的复杂信道特性,设计了基于数字信号处理(DSP)的高速数字自适应多载波水声语音通信系统,采用MFSK调制技术、数据精确同步技术以及低噪PGA技术,有效地降低了误码率.通过对其关键技术的性能仿真和分析,以及在2 km长、1.5 m深的恶劣环境中实测,该系统表现出很好的实时性和良好的语音恢复性能,传输距离大于2 km,误码率小于10-3.

摘要：针对编码器日趋小型化的技术要求,本文提出一种全新的编码方式和独特的读数头设计结构,成功研制出了超小型准绝对式编码器。该新型编码器采用准绝对式编码方式,即距离编码与增量式编码进行组合编码,只用两圈码道进行编码,极大减少码道数量,整周设多个绝对参考位置,可迅速获得绝对位置信息。采用单读数头结构和相位补偿技术,缩小结构尺寸,直径Φ25mm,经过电子学细分后可到达16位的分辨力,从而实现高精度编码器小型化。

摘要：在功率半导体器件中,高的反向击穿电压和低的正向导通电阻之间的矛盾关系是影响其发展的主要因素之一,选用超结结构替代功率半导体器件中的传统电压支持层能够有效缓解这一矛盾关系。该文设计和实现了一种超结肖特基二极管,其中的电压支持层采用P柱和N柱交替构成的超结结构。在器件的制作方面,选用成熟的单步微电子工艺,通过4次N型外延和4次选择性P型掺杂来实现超结结构。为便于对比分析,设计传统肖特基二极管和超结肖特基二极管的电压支持层厚度一致,且超结结构中P柱和N柱的杂质浓度均和传统肖特基二极管的电压支持层浓度一致。测试得到传统肖特基二极管的反向击穿电压为110 V,而超结肖特基二极管的反向击穿电压为229 V。表明采用超结结构作为功率半导体器件的电压支持层能够有效提高反向击穿电压,同时降低器件的正向导通电阻,并且当P柱区和N柱区内的电荷量一致时器件的击穿电压最高。

摘要：研究一类不完全转移率信息的Markov跳变奇异系统的H∞控制问题,提出连续Markov跳变奇异系统的新型有界实引理,并将其推广到不完全转移率条件.进一步设计H∞状态反馈控制器,使得闭环系统在转移率部分未知的条件下随机可容许,且满足H∞性能H.所得结论涵盖了奇异矩阵模态依赖情形,且表示为严格线性矩阵不等式形式,利于工程实现.最后,通过仿真算例表明了所提出方法的有效性和优越性.