摘要：Swirl recovery vanes（SRVs） are a set of stationary vanes located downstream from a propeller, which may recover some of the residual swirl from the propeller, hoping for an improvement in both thrust and efficiency. The SRV concept design for a scaled version representing the Fokker 29 propeller is performed in this paper, which may give rise to a promotion in propulsive performance of this traditional propeller. Firstly the numerical strategy is validated from two aspects of global quantities and the local flow field of the propeller compared with experimental data, and then the exit flow together with the development of propeller wake is analyzed in *** kinds of SRV are designed with multiple circular airfoils. The numerical results show that the swirl behind the propeller is recovered significantly with Model V3, which is characterized by the highest solidity along spanwise, for various working conditions, and the combination of rotor and vane produced 5.76% extra thrust at the design point. However, a lower efficiency is observed asking for a better vane design and the choice of a working point. The vane position is studied which shows that there is an optimum range for higher thrust and efficiency.

摘要：申苏浙皖高速公路K44边坡由于受太湖区域地质构造的影响,岩体条件复杂。经应用研制的公路边坡稳定性评价设计系统,通过计算稳定性系数,进行敏感性分析,计算加固总力等,对边坡进行全面综合性的稳定性评价,收到了良好效果。

摘要：依据已完成的卸船机整机吊装项目,介绍卸船机整机吊装上岸方案,阐述卸船机整机吊装施工中的要点及难点。卸船机整机吊装可以缩短项目时间,也能提升码头作业效率。

摘要：为进一步揭示土壤侵蚀的内在规律,以某一试验小区为例,通过模拟不同地表粗糙度,分析了不同雨强条件下的坡面侵蚀产沙及泥沙颗粒粒径变化特征。结果表明:相同雨强和降雨历时下,粗糙度对坡面径流率、水流功率、径流含沙量和产沙率有显著影响;侵蚀泥沙的搬运形式与雨强和粗糙度均有关,而不同泥沙颗粒搬运方式是引起不同粗糙度坡面侵蚀产沙分异的重要原因。因此,坡面侵蚀产沙模型中应综合考虑地表粗糙度和泥沙粒径信息。研究成果可为水土保持规划设计和水土保持措施优化配置提供一定依据。

摘要：介绍了直梁曲线桥设计和施工过程中墩台中心及直梁中心测设资料的严密计算方法,并介绍了桥梁支座预留孔的计算方法。

摘要：针对下胶辊高精度圆弧槽难以加工的情况,从测量装置的测量精度的提高、机床加工精度的提高和零件加工效率的提高三个方面入手,提出了一种系统的加工和测量方法。通过设计V型测量工装,可在工具磨床加工过程中对高精度圆弧槽进行测量,通过设计分度工装来提高零件的加工效率,通过修整砂轮的方法来满足高精度圆弧槽的加工精度要求。该方法在实际生产中应用后,加工出了满足图纸要求的零件,此零件也得到了用户的认可。

摘要：为了解决新车短周期开发带来的量产阶段质量频发问题,G公司以X58为试点车型创造性开展了全面检证,以产生变化的重点模块/总成为单位成立全面检证小组并行同步开展检证工作,按数模设计同步工程阶段和PT试制阶段两个阶段开展,重点回答产品结构变化、目标实现功能、工艺可行性、定位连接合理性、现场装配性、零件实物规格及素性、静态装配质量、整车及耐久质量八大问题,确保在前期问题全面显在化并快速解决,实现X58车型短周期开发并高质量投产。

摘要：The Bohai Sea is one of the southernmost areas for sea ice formation in the northern *** ice disasters in this body of water severely affect marine activities and the safety of coastal *** this study,we analyze the variation characteristics of the sea ice in the Bohai Sea and establish an annual regression model based on predictable mode analysis *** results show the following:1)From 1970 to 2018,the average ice grade is(2.6±0.8),with a maximum of 4.5 and a minimum of *** Bay(LDB)has the heaviest ice conditions in the Bohai Sea,followed by Bohai Bay(BHB)and Laizhou Bay(LZB).Interannual variation is obvious in all three bays,but the linear decreasing trend is significant only in BHB.2)Three modes are obtained from empirical orthogonal function analysis,namely,single polarity mode with the same sign of anomaly in all of the three bays and strong interannual variability(82.0%),the north–south dipole mode with BHB and LZB showing an opposite sign of anomalies to that in LDB and strong decadal variations(14.5%),and a linear trend mode(3.5%).Critical factors are analyzed and regression equations are established for all the principal components,and then an annual hindcast model is established by synthesizing the results of the three *** model provides an annual spatial prediction of the sea ice in the Bohai Sea for the first time,and meets the demand of operational sea ice forecasting.

摘要：在油菜果荚脱粒过程中,脱粒方式及其功耗是影响脱净率、破损率等指标的重要因素,是设计油菜联合收割机脱粒装置的关键。该文采用搓擦、碾压和冲击等不同脱粒方式,对完熟期油菜果荚进行了脱粒试验,研究了油菜果荚脱净率和脱粒功耗之间的关系,并对3种脱粒方式的脱粒效果进行了对比分析。试验表明,果荚脱净率和功耗之间呈对数关系;在单位脱粒量功耗大于0.5J/g后,相同脱粒功耗下,揉搓脱粒的脱净率高于碾压脱粒和冲击脱粒。结果表明油菜联合收割机脱粒装置宜设计为冲击脱粒和搓擦脱粒组合的脱粒方式。该研究可为油菜脱粒方式的选择和结构设计提供参考。

摘要：为了能够准确检测出多路精量排种器的合格指数、漏播指数、重播指数等排种性能指标值,确保精量排种器的排种质量,利用检测排种时间间隔间接获得排种粒距的原理,设计了一种多路精量排种器性能检测系统。系统采用工业触控平板电脑以及MSP430单片机系统构建上下位机结构模式,下位机采用光纤及光电传感器感应获得精量排种器排种及转速脉冲序列信号,利用单片机系统时间扑捉中断资源实时记录种子间隔时间和排种盘转速,经串口握手传输协议将编码后的信息传输至计算机系统。上位机从排种性能指标的结构分布以及排种频率指标两方面对排种数据进行分析并得到各路的合格指数、重播指数、漏播指数等性能指标。验证试验测试表明,所设计的带有校验检错功能的串口通信交互协议能够实现上下位机数据的准确传输,在15~300 r/min转速范围内,该检测系统能够对多路不同排种性能指标值的转盘进行准确检测;在油菜精量排种器性能检测试验台上利用高速摄影系统对比试验表明系统时间检测最大误差为0.876 ms,最大相对平均误差为0.192 ms,检测指标综合误差为0.87%,最大综合误差为3.98%。该研究为'一器多行'集排器的排种性能检测及优化排种器设计提供了参考。