摘要：Advanced geological prediction is a crucial means to ensure safety and efficiency in tunnel ***,diff erent advanced geological forecasting methods have their own limitations,resulting in poor detection *** multiple methods to carry out a comprehensive evaluation can eff ectively improve the accuracy of advanced geological prediction *** this study,geological information is combined with the detection results of geophysical methods,including transient electromagnetic,induced polarization,and tunnel seismic prediction,to establish a comprehensive analysis method of adverse ***,the possible main adverse geological problems are determined according to the geological ***,various physical parameters of the rock mass in front of the tunnel face can then be derived on the basis of multisource geophysical ***,based on the analysis results of geological information,the multisource data fusion algorithm is used to determine the type,location,and scale of adverse *** advanced geological prediction results that can provide eff ective guidance for tunnel construction can then be obtained.

摘要：为提升铁氧体零件缺陷检测的精度和自动化程度,提出一种基于卷积神经网络的铁氧体零件裂缝检测方法。根据铁氧体零件的自身形状特点,设计一种基于ResNet-18的四分类神经网络,通过9420张128×128分辨率的铁氧体零件图片对该网络进行训练,在验证集上达到了97%的分类准确率。提出一种滑动子区域计分方法,与训练好的神经网络模型结合,在测试集上可达到97.9%的检测精度。验证结果表明,该方法能够检测宽度在0.1 mm左右、长度超过0.2 mm的裂缝。

摘要：为解决在训练物体六自由度位姿估计神经网络时,人工标注真实场景数据集困难的问题,提出一种自动生成大量单目六自由度位姿估计数据集的方法,可提高数据集标注效率和精度。考虑采集图象环境的光照、物体遮挡等条件,以单目RGB相机、物体三维模型作为输入,在运动恢复结构(structure form motion,SfM)算法框架中添加尺度先验信息约束,实现在真实场景快速生成大量用于六自由度位姿估计训练的数据集。以生活用品为例,分别制作无遮挡、有遮挡数据集,与现有六自由度位姿估计数据集作对比,使用神经网络算法验证根据该方法制作出数据集的可行性与有效性。

摘要：Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and *** cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available *** we reported an artificial cascade biocatalysis comprising an epoxide hydrolase,an alcohol dehydrogenase,and a reductive aminase or an amine *** can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields(up to 95%)and excellent stereoselectivity(up to 98%de)starting from readily available cyclohexene oxide without isolation of the ***,the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.

摘要：With the continued expansion of oil and gas exploration,both in the eastern and western regions,the quality of seismic acquisition has become a key factor in oil and gas exploration in complex ***,conventional seismic acquisition methods cannot effi ciently avoid challenging acquisition locations and produce high-quality seismic *** this regard,based on the curvelet transform,this paper proposes an irregular seismic acquisition method,which utilizes the high-precision characteristics of the curvelet transform and simulated annealing algorithm to establish a method for the evaluation of the coherence of irregular sampling matrices and design of observation *** method was verifi ed using forward simulation and actual acquisition *** results suggest the superior quality of seismic data gathered in complicated areas through this method over those acquired using traditional methods,which can provide technical guidance for the design of observation systems in complex areas.

摘要：为解决淬火状态下30Cr3超高强度钢在真空电子束焊接时易产生冷裂纹、过热区脆化及热影响区软化等问题,在对材料性能分析的基础上,采取了提高真空度、提高加速电压、焊前预热、选择合适的焊接速度以及焊后回火处理等措施。结果表明,金相分析未发现缺陷,试样断口为塑性断裂,试片焊缝强度系数达0 96,产品爆破压力pb>27MPa。证明该方法可满足设计要求的焊接接头,为固体火箭发动机壳体的生产提供了新的工艺方法。

摘要：In topology optimization of structures considering flexibility, degenerated optimal solutions, such as hinges, gray areas and disconnected structures may appear. In this paper, built upon the newly developed morphable component based topology optimization approach, a novel representation using connected morphable components(CMC) and a linkage scheme are proposed to prevent degenerating designs and to ensure structure integrity. A lower bound condition of the thickness of each component is also incorporated to completely remove the smallest components in an optimal configuration. Designs of flexible structures, such as compliant mechanism design, maximum compliance structure design, and design of low-frequency resonating micro devices are studied to validate the proposed methodology. Our work demonstrates that the new methodology can successfully prevent degeneration solutions and possesses other advantages, such as minimum member size control in topology optimization of flexible structures.

摘要：为满足激光通信系统的共形设计和实现轻小型化的空间激光通信组网,设计一种应用于机载平台下的基于偏振光栅与快反镜(FSM)的新型单探测器复合轴系统。针对旋转偏振光栅实际应用与理论之间的差异,将偏振光栅光束偏转问题与目标脱靶量之间进行关联,定义了目标位置与双偏振光栅角度关系,进行了偏振光栅光束偏转坐标构建及解耦。随后对复合系统偏振光栅单元与FSM单元进行设计,通过目标闭环试验检测了系统跟踪性能,结果表明,在5°@0.2 Hz载体扰动情况下,双偏振光栅方位轴、俯仰轴脱靶量闭环残差分别为126.1002μrad(RMS)与149.5309μrad(RMS),FSM方位轴、俯仰轴脱靶量闭环残差分别为3.4921μrad(RMS)与4.0131μrad(RMS),动态目标闭环控制双轴精跟踪残差为5.3197μrad(RMS),相比于Risley棱镜,光束偏转范围提升4倍,精度提升45.8%。整个跟踪过程中,两偏振光栅旋转角度值连续且平稳变化,满足轻量型机载平台对光电跟瞄设备的使用需求。

摘要：采用低压合成的Ｃｏ（ＣＯ）４ －甲醇溶液催化剂，并配以高回收钴工艺，对氯苄、ＣＯ 羰化合成苯乙酸工艺进行了小试和扩试，得到最适宜的反应条件：反应温度ｔ＝ ５５ ℃，常压，ｎ［Ｃｏ（ＣＯ）４ － ］／ ｎ（ 氯苄） ＝ ０ ．０２ ，ＣＯ 连续通入，反应时间４ ～５ｈ 。工艺扩试后，苯乙酸收率达到８５ ％ ，纯度达到９９ ％ ，钴回收率达到９０ ％ 以上。

摘要：近年来,随着乙烯、丙烯等脂肪族不饱和化合物用量日益剧增,利用选择性加氢脱氯技术将多氯代烃转化为这类高附加值化学品受到学术界和工业界的广泛关注,其核心在于高性能催化剂的设计与制备。首先综述了加氢脱氯合成烯烃用催化剂的研究进展,重点归纳总结了催化剂活性组分如Pd、Pt的几何结构、电子结构以及催化助剂、制备方法等对烯烃生成的影响规律。其次,从动力学、理论计算等方面对催化选择性加氢脱氯合成烯烃反应机理进行了概述。此外,总结了造成催化剂失活的四个主要因素。最后指出,基于金属氟化物在高温强腐蚀性HCl气氛下结构保持稳定、易于实现调控载体与活性组分之间相互作用等特点,设计制备金属氟化物负载型Pd、Pt催化剂,是实现温和条件下选择性加氢脱氯合成烯烃的一个重要途径。