轴流压气机尾流撞击效应机理的数值模拟

通过精确给定转子进口边界条件,以模拟上游静子尾迹对转子流场的影响,这样利用单排的计算结果模拟转/静干涉引起的非定常流动对流场气动参数的影响,因为相邻叶片排的叶片数不同,从而避免传统方法中常用的叶片数约化存在的难以正确模拟非定常激励频率的问题,对计算时间和计算能力的要求也可减少.针对一个低速转子的数值模拟结果显示,如果能合理地组织来流尾迹的扫过频率和尾迹亏损的幅度,对转子气动性能的改善是很显著的,从而为风扇/压气机中控制和利用非定常流动提供了一个可行的方向.     

0.66m直径对旋式轴流风机的设计和性能估算

对旋式轴流风机具有压力增益大、效率高、结构简单和轴向尺寸小等优点 ,但目前还缺乏现成的设计方法可供借鉴 ,为此笔者提出了一个可行的设计思路及方法 ,即按照常规单级后扭型和预扭型风机 ,分别设计对旋式风机的前后两级桨叶 ,然后修正它们之间的相互干扰。给出了这种设计方法的要点。讨论了两级桨叶的负载分配和前后桨叶各参数之间的关系。根据前后两级桨叶绕流过程的不同 ,重点考虑了它们之间的相互干扰 ,提出修正干扰的方法。进行风机性能估算 ,对缩短研制周期、及时修改设计参数、提高设计水平都是很有益的。样机试验表明 ,风机的设计和性能估算都是成功的     

Using only observation station data for PPP ambiguity resolution by UPD estimation

This article proposes a new method for uncalibrated phase delay (UPD) estimation to improve the accuracy of precise point positioning (PPP), which uses only observation station data. This means that the station used to generate the UPDs is the same station to which they are applied. First, dual-frequency observation equations based on a raw PPP model are developed. Then, the UPDs are calculated from integer linear combinations of float ambiguities. Third, with the UPD corrections, the least-squares ambiguity decorrelation adjustment (LAMBDA) method is utilized to obtain the integer ambiguities. Since only observation station data are used for UPD estimation, the partial ambiguity resolution (PAR) method is adopted to increase the possibility of finding a subset of integer ambiguities. The UPD estimation and ambiguity resolution are performed in each epoch. To obtain the correct integer ambiguity, the ratio test and success rate (bootstrapping) are used to evaluate the estimated integer ambiguity. Finally, by treating the integer ambiguities as constants, fixed solutions can be obtained. Quality control is also applied throughout the entire data processing procedure to obtain high quality float and fixed solutions. Data from 22 stations of the International Global Navigation Satellite System (GNSS) Service (IGS) in East Asia on day of year (DOY) 206, 2017, are used to verify the feasibility of this method. The experimental results show that compared with the float solution, the proposed method can significantly improve the accuracy in the east, north and up directions by 24%, 21% and 18% for static PPP and 36%, 18% and 34% for dynamic PPP, respectively. However, the accuracy of the proposed method is still lower than that of the fixed solutions obtained by the PRIDE-PPPAR software, in which the fractional cycle bias is computed based on reference network data. These findings sufficiently show that the proposed method can offer better solution accuracy than the float solution. However, the quality of the UPDs estimated only from observation station data is not as good as that of the estimates obtained based on reference network data.     

中美大学生职业生涯规划指导模式的比较

多年的高校扩招,使大学生就业难成为全社会持续关注的热点.就业难的主要原因是人职难以匹配,其症结可归结为大学生没有清晰的职业发展目标,缺乏职业规划.大学生职业生涯规划指导在我国起步较晚,仅有十几年的时间,这一工作尚处于摸索阶段,难免问题多、效果不佳;而大学生职业生涯规划起源于美国,已经有上百年的发展历史,美国并且已经探索出一套行之有效的职业生涯规划指导模式.文章对中美高校职业生涯规划指导进行分析和对比,查找我国职业生涯规划指导存在的问题,总结美国职业生涯规划教育的经验,通过借鉴美国高校的经验,并结合我国的实际情况,探索适合我国大学生职业生涯规划指导的新模式.     

Update Chain-based Approach for Checking Route Oscillation of BGP

This paper presents a novel approach for checking route oscillation of border gateway protocol(BGP) quickly,by which the privacy of routing policies of autonomous system(AS) can be respected.Firstly,route update chain tag(RUCT) is constructed to track the forwarding of update report,and local routing library is made to record the changing history of update report.Then route oscillation can be identified by analyzing correlative state of RUCT and local routing library.The characteristic of this approach is that an arbitrary AS can check route oscillation alone only by sharing its network ID,which greatly respects the pri-vacy of routing policies for each AS.This paper shows that both looping in RUCT and consecutive positive-negative report in local record are sufficient conditions for route oscillation.Comparative experiments demonstrate the availability and efficiency of the proposed approach.     

基于职业能力的高职酒店管理专业培养模式构建

重视学生职业能力的培养，学生才能真正成为人才，企业才会真正满意。某学院酒店管理专业一直以来始终坚持以培养学生的职业能力为核心；依靠学校和酒店企业二个平台，以学校教育为：主，以酒店培训为辅；构建以职业能力培养为核心的课程体系。通过积极推进教学改革的实践，该学院酒店管理专业取得了一定的成效。     

飞机实测环境温度数据处理方法研究

可靠性试验所使用的综合环境应力,决定着可靠性试验的有效性。准确的综合环境应力来自于飞行测试,如何将实测数据转换成试验应力,要解决一系列数据处理技术问题。本文参考国外资料及GJB899-90《可靠性鉴定和验收试验》编制试验剖面的基本思想,建立了一种完整的军用飞机实测温度数据转换为综合环境应力的方法。利用实测的飞机舱温数据,对提出的数据处理方法进行了检验,结果满足可靠性试验对温度试验应力的精度要求。此处理方法可直接应用于工程实际,编制军用飞机可靠性试验剖面。     

书法与绘画

书法与绘画是中国古代艺术门类中两种极为重要的艺术形式，其强劲的生命力与影响力延续至今。本文从书画同源、书画相通、书画互补、书画尚韵、书画传神这五个方面，详细阐述了书法与绘画之间的关系，为理解以及把握这两种文化形态的内涵与实质理清了头绪和脉络。     

智能型减压器试验台的研制

主要介绍了基于硬件设备和软件编程基础上的智能型减压器试验台的设计与应用。测试系统保留了最通常的手动操作系统，增加了全新的自动数据采集系统。试验台可精确、同步测量高入口压力值时的瞬时出口压力值，同时，增加了入口压力控制系统，大大提高了工作效率。     

包覆药柱界面粘结质量的无损检测

利用错位电子散斑干涉技术，对包覆药柱界面粘结质量无损检测方法进行了研究，分析了影响检测结果的间距、图像判读、加载量、灵敏度和内应力等关键因素。试验结果表明，此方法可以检测最小直径3.6mm的人工脱粘区。