摘要：Increasing the injection pressure has been proven an effective method to enhance performance and reduce pollutant of diesel *** the increase of the injection pressure,the cavitation damage problem inside common rail fuel injector is more significant,which has direct influences on reliability of diesel *** the most studies so far have focused on cavitation occurred in injector nozzle and its atomization characteristics,few researchers studied the cavitation phenomenon in fuel injector control *** due to the complexity of flow field and difficulty of experiment,the cavitation in control valve could not be fully described by existing *** this paper,the two-dimensional visualization experiment and numerical simulation of control valve was implemented to acquire the image of cavitation intuitively and validate the simulation method and *** a new structure design of control valve named convergent model was presented for *** origin model and convergent model with different valve lifts were simulated in three *** results showed that the sheet cavitation occurred at the surface of seal cone and steel ball then turned to cloud cavitation in downstream *** intensity of cavitation increased with the increase of valve *** model could efficiently reduce the cavitation intensity near the seal *** research could provide references for engineering optimization design of control valve.

摘要：针对农村偏远地区通信不畅的临时突发性问题,该文提出一种自适应的多无人机(UAV)辅助通感一体化(ISAC)机制,在地面用户和感测目标呈簇状随机分布的情况下,通过合理调度多无人机实现覆盖式通信保障,为无人机使能的通感一体系统提供了一种新的解决思路和方案。该文主要研究了无人机空间部署及其对地面设备的波束成形等问题,在空地关联约束条件下,系统可通过优化无人机的通信和感知波束成形变量组,最大限度地提高用户传输可达速率的下限,同时保证基本的通感需求。为了有效解决所考虑的非凸优化问题,该文借助基于高斯核的均值漂移算法(MS),用以处理关联策略中的混合整型线性问题,此外,结合2次变换与连续凸逼近(SCA)的相关技巧,采用块坐标下降(BCD)的方式优化波束成形,以获取次优解。数值结果验证了自适应机制的有效性。

摘要：目前燃气轮机出厂测试时，液压执行机构的开关时间测试及紧急切断时间测试不能满足实际运行时阀门位置开度精确控制的要求。结合燃气轮机气体燃料控制阀组及其液压执行机构的设计与试验技术相关的基础研究课题中的多项性能技术指标，研制了执行机构试验件，搭建了基于虚拟仪器的控制阀多项性能测试装置，对该执行机构试验件进行了多项性能测试，包括开关试验、紧急切断试验、控制误差试验、重复性误差试验及回差试验等。试验件的性能测试结果满足课题技术指标的要求。上述指标测试方案可为后续项目的出厂测试提供参考。

摘要：为实现信号快速传输,提高光通信系统稳定性,设计基于嵌入式技术的光通信信号智能处理系统。构建光通信信号智能处理系统框架,将采DSP处理模块嵌入到光通信系统中,以LED阵列作为光源,获得光通信原始信号,在DSP中完成RS编码、截断的PPM调制,将其作用到LED上实现光通信信号的发送,经过信道传输后,通过凸透镜聚集传送光束并由探测器阵列接收光信号,采用Berlekamp-Massey算法完成信号解译,利用由高带宽增益积运算放大器、全差分运算放电器、限幅放大器构成两极信号处理电路完成原始输入信号的复原。实验结果表明:该系统可保证5 km通信距离下光通信信号的稳定传输,随着通信距离的增长,误码率呈小幅度变大,2.5 km通信距离内,误码率为0,可实现输入信号的准确恢复,收发端信噪比不低于74 dB,信号处理性能突出。

摘要：zhang Wanquan,a native from southern Zhejiang Province,came to the port city Tianjin to make a living on casting pen containers and flower *** son zhang *** and adroit,followed him to learn how to make articles in his *** other day jinior zhang showed the clay animals he made

摘要：目的:分析国内外养老机器人研究现状、热点与趋势。方法:从Web of Science和CNKI中检索养老机器人相关文献,使用CiteSpace 6.2.R4对纳入文献进行文献计量与可视化分析。结果:检索并纳入中文文献443篇、英文文献1656篇。中英文文献年度发文量均呈明显上升趋势,中文文献数量较少,发文量增速较低;机构间合作紧密度较低,主要发文机构为高校;英文关键词包括技术、痴呆、设计等,中文关键词包括人工智能、智慧养老、人机交互等,中英文关键词聚类分别得到9个主要聚类标签,英文聚类标签为人机交互、腿部运动、跌倒检测等,中文聚类标签为外骨骼、人工智能、人机交互等;中英文关键词突现分别得到15个、20个关键词,突现强度最高的中英文关键词分别为动力学和人工智能。结论:未来养老机器人领域应加强产、学、研深度融合,提高人才培养成效,增进科技成果转化水平,同时加强数据安全及隐私保护,注重多模态设计与人工智能前沿技术应用。

摘要：为推进中国铁路兰州局集团有限公司(简称:兰州局)全面预算管理、规范预算项目管理流程和强化执行过程控制,开发了铁路企业项目预算管理信息系统。该系统实现项目预算信息电子化集中管理,依据兰州局预算管理办法,设计了规范、透明、可溯源的预算项目申报与审批流程,采用Drools规则引擎实现可配置的预算项目管理流程,使预算项目管理工作更加快捷、高效、规范,增强了管理流程的灵活性和应用程序的可维护性;使用分布式对象存储系统MinIO和在线文件预览工具kkFileView,实现项目附件文档集中管理及安全预览与下载,确保项目附件文档不可篡改和审核严格;集成功能强大的图表绘制引擎,实现预算项目数据可视化和多种定制化图表,提供直观、便捷的项目执行监控与异常预警,可为提高铁路企业预算项目管理效率、强化风险控制提供强有力的技术手段。

摘要：基于产业结构的规律性构成探讨创意产业链的构成,从关联结构关系中探讨可以施以润滑和推进的内容,由此探讨当今创新设计教育的方式和主要内容结构。

摘要：Referring to the questionnaire surveys and literature materials, this paper tries to discuss the causes of high school students＇ English reading barriers and its possible strategies to improve their English reading ability. This paper used a questionnaire survey to collect data with 188 grade one high school students as research subject. The result shows English reading barriers are mainly divided into two parts, language factors and non-language factors. Language factors include vocabulary barriers, grammar barriers, discourse barriers and culture background barriers. Non-language factors mainly include psychological factors, reading habits, reading interest and reading strategies. It is suggested that joint efforts from teachers and students are needed to solve the reading barriers. Teachers should help students increase vocabulary accumulation, strengthen grammar knowledge, develop their discourse comprehension skills and teach culture knowledge in class. Students need to overcome psychological factors, develop good reading habits, do a series of trainings on reading, give immediate feedbacks and sum up reading experiences.

摘要：目的:建立一种简便、高效的端粒酶活性检测方法,用于评价间充质干细胞产品的成瘤性风险。方法:针对端粒酶催化亚基(TERT)的保守结构域设计特异性引物和探针,并对TERT基因的引物和探针进行优化筛选,同时设置内参基因的引物和探针,在一个反应体系内使用双色荧光探针进行多重定量PCR反应,建立RT-qPCR探针法。应用该法对人间充质干细胞中是否表达TERT基因来间接判断细胞中是否存在端粒酶活性。结果:该方法可稳定特异地检测到阳性对照细胞293T/17的TERT基因,Ct平均值为23.96,RSD为1.5%。内参基因GAPDH均可以正常检出,Ct平均值为14.13,RSD为1.3%。阴性对照细胞MRC-5内参基因GAPDH可以正常检出,Ct平均值为12.81,RSD为0.46%,TERT基因未检出,该细胞端粒酶活性为阴性。人间充质干细胞HMSC内参基因GAPDH可以正常检出,Ct平均值为13.01,RSD为3.8%,TERT基因未检出,人间充质干细胞HMSC的端粒酶活性为阴性。结论:本研究建立的RT-qPCR探针法重复性好,特异性高,能够准确检测端粒酶阳性细胞催化亚基mRNA的转录。可用于间充质干细胞的端粒酶活性分析,间接评估间充质干细胞成瘤性风险。