摘要：针对现有点云局部特征描述算法时效性和紧凑型不能满足实际应用需求的问题,提出一种二进制多层切片距离特征描述算法(B-MSD)。首先在特征点处建立了一种稳健的局部参考坐标系;然后设计了两种多层切片和子区域划分方式并计算平均距离,以提取点云局部三维形状特征;最后通过量化的方法将各子区域计算的平均距离转化为二进制码串,串联所有码串生成最终的二进制描述子。在多个公开点云数据集上与几个经典描述子进行仿真对比,结果表明,在鉴别力更强的基础上,上述算法的紧凑性、计算效率和匹配速度方面综合表现更好。3D目标检测和点云配准应用实验也验证了上述算法的有效性。

摘要：为了解温度变化对沥青混凝土强度及剪胀特性的影响,开展了-1、5、10、15℃下的沥青混凝土三轴剪切试验。试验结果表明:沥青混凝土的强度变形特性与温度有密切关系,负温时,表现出明显的应变软化和剪胀性,随着温度的升高,应力-应变曲线转变为应变硬化型,且剪胀性减弱;沥青混凝土抗剪强度随温度升高而减小,且黏聚力的降低幅度明显大于内摩擦角,当温度从-1℃升高到15℃时,内摩擦角减小了4.7°,而黏聚力由1.11 MPa减小到0.28 MPa;沥青混凝土剪胀角随轴向应变增大而增大,并趋于稳定,两者关系可采用双曲线函数进行拟合;双曲线模型参数与温度有较好的相关性,可进一步考虑剪胀角随温度的变化情况。研究成果可为沥青混凝土的热-力耦合本构模型建立提供参考。

摘要：Metalenses with achromatic performance offer a new opportunity for high-quality imaging with an ultracompact configuration;however,they suffer from complex fabrication processes and low focusing *** this study,we propose an efficient design method for achromatic microlenses on a wavelength scale using materials with low dispersion,an adequately designed convex surface,and a thickness profile *** taking into account the absolute chromatic aberration,relative focal length shift(FLS),and numerical aperture(NA),microlens with a certain focal length can be realized through our realized map of geometric ***,the designed achromatic microlenses with low-dispersion fused silica were fabricated using a focused ion beam,and precise surface profiles were *** fabricated microlenses exhibited a high average focusing efficiency of 65%at visible wavelengths of 410-680 nm and excellent achromatic capability via white light ***,the design exhibited the advantages of being polarization-insensitive and *** results demonstrate the effectiveness of our proposed achromatic microlens design approach,which expands the prospects of miniaturized optics such as virtual and augmented reality,ultracompact microscopes,and biological endoscopy.

摘要：针对室内复杂场景中,图像语义分割存在的特征损失和双模态有效融合等问题,提出了一种基于编码器-解码器架构的融合注意力机制的轻量级语义分割网络.首先采用两个残差网络作为主干网络分别对RGB和深度图像进行特征提取,并在编码器中引入极化自注意力机制,然后设计引入双模态融合模块在不同阶段对RGB特征和深度特征进行有效融合,接着引入并行聚合金字塔池化以获取区域之间的依赖性.最后,采用3个不同尺寸的解码器将前面的多尺度特征图进行跳跃连接并融合解码,使分割结果含有更多的细节纹理.将本文提出的网络模型在NYUDv2数据集上进行训练和测试,并与一些较先进RGB-D语义分割网络对比,实验证明本文网络具有较好分割性能.

摘要：油田分注智能控制软件能够自动对每个注水层信息进行实时监测与控制,实现精细分注。软件通过协议整合实现远程实时读取井下各层注水量、温度等数据,具有实时调整各层配水器水嘴开度大小,验封测调、压力恢复测试,等功能。在内容上,兼容各厂家的数据信息,满足各个厂家的数据涵盖需求,减少数据冗余和工作人员工作量。界面风格上,满足各个厂家的审美需求以及操作规范,实现了规范化、统一化,降低维护成本和人员工作量。为油藏分析提供大量的数据支撑,具有较高的推广应用价值。

摘要：地铁列车车门调试时,需进行多次开关门试验,每次测试次数和周期均不同。传统的测试装置无法快速修改开关门测试次数和周期,为提高地铁车辆开关门试验效率,研制了基于7寸触摸屏的地铁车辆开/关门信号模拟发生器。该装置由7寸触摸屏和主板组成,两者通过USART进行通信。主板为自主开发的一块集成电路板,以Atmega16单片机为核心,控制2路高/低电平信号驱动地铁列车开/关门信号和1个微型蜂鸣器信号。该设计方案能够完全实现预设功能,具有智能化优点,值得在行业内推广应用。

摘要：The infamous type Ⅳ failure within the fine-grained heat-affected zone (FGHAZ) in G115 steel weldments seriously threatens the safe operation of ultra-supercritical (USC) power *** this work,the traditional thermo-mechanical treatment was modified via the replacement of hot-rolling with cold rolling,i.e.,normalizing,cold rolling,and tempering (NCT),which was developed to improve the creep strength of the FGHAZ in G115 steel *** NCT treatment effectively promoted the dissolution of preformed M_(23)C_(6)particles and relieved the boundary segregation of C and Cr during welding thermal cycling,which accelerated the dispersed reprecipitation of M_(23)C_(6) particles within the fresh reaustenitized grains during post-weld heat *** addition,the precipitation of Cu-rich phases and MX particles was promoted evidently due to the deformation-induced *** a result,the interacting actions between precipitates,dislocations,and boundaries during creep were reinforced *** this strategy,the creep rupture life of the FGHAZ in G115 steel weldments can be prolonged by 18.6%,which can further push the application of G115 steel in USC power plants.

摘要：当涡旋压缩机在某些特殊工况运行时,液态制冷剂会进入压缩机,进而部分液态制冷剂进入涡旋腔,对涡旋壁和十字环产生很大的冲击力。当进入的液态制冷剂量超过涡旋腔所能承受的极限,对涡旋和十字环造成损坏并导致压缩机失效。在新压缩机产品开发过程中,传统的方式是通过试验方法去验证压缩机的抗液击性能,但这种方法需要组装样机并在实验室进行测试,时间长且成本高。文章提出了一种基于两相流模型预测涡旋压缩机抗液击性能的方法,通过该方法,在新产品设计的早期阶段无需试验就可以预测涡旋压缩机的抗液击性能,能够有效地降低项目成本且加快产品上市时间。

摘要：Al is considered as a promising lithium-ion battery(LIBs)anode materials owing to its high theoretical capacity and appropri-ate lithation/de-lithation ***,its inevitable volume expansion causes the electrode structure instability,leading to poor cyclic ***’s worse,the natural Al2O3 layer on commercial Al pellets is always existed as a robust insulating barrier for elec-trons,which brings the voltage dip and results in low reversible ***,this work synthesized core-shell Al@C-Sn pellets for LIBs by a plus-minus *** this proposal,the natural Al2O3 passivation layer is eliminated when annealing the pre-introduced SnCl2,meanwhile,polydopamine-derived carbon is introduced as dual functional shell to liberate the fresh Al core from re-oxidization and alle-viate the volume *** from the addition of C-Sn shell and the elimination of the Al2O3 passivation layer,the as-prepared Al@C-Sn pellet electrode exhibits little voltage dip and delivers a reversible capacity of 1018.7 mAh·g^(-1) at 0.1 A·g^(-1) and 295.0 mAh·g^(-1) at 2.0 A·g^(-1)(after 1000 cycles),***,its diffusion-controlled capacity is muchly improved compared to those of its counterparts,confirming the well-designed nanostructure contributes to the rapid Li-ion diffusion and further enhances the lithium storage activity.

摘要：Traditional tumor models do not tend to accurately simulate tumor growth in vitro or enable personalized treatment and are particularly unable to discover more beneficial targeted *** address this,this study describes the use of threedimensional(3D)bioprinting technology to construct a 3D model with human hepatocarcinoma SMMC-7721 cells(3DP-7721)by combining gelatin methacrylate(GelMA)and poly(ethylene oxide)(PEO)as two immiscible aqueous phases to form a bioink and innovatively applying fluorescent carbon quantum dots for long-term tracking of *** GelMA(10%,mass fraction)and PEO(1.6%,mass fraction)hydrogel with 3:1 volume ratio offered distinct pore-forming characteristics,satisfactorymechanical properties,and biocompatibility for the creation of the 3DP-7721 *** analysis and quantitative real-time fluorescence polymerase chain reaction(PCR)were used to evaluate the biological properties of the *** with the two-dimensional culture cell model(2D-7721)and the 3D mixed culture cell model(3DM-7721),3DP-7721 significantly improved the proliferation of cells and expression of tumor-related proteins and ***,we evaluated the differences between the three culture models and the effectiveness of antitumor drugs in the three models and discovered that the efficacy of antitumor drugs varied because of significant differences in resistance proteins and genes between the three *** addition,the comparison of tumor formation in the three models found that the cells cultured by the 3DP-7721 model had strong tumorigenicity in nude *** evaluation of the levels of biochemical indicators related to the formation of solid tumors showed that the 3DP-7721 model group exhibited pathological characteristics of malignant tumors,the generated solid tumors were similar to actual tumors,and the deterioration was *** research therefore acts as a foundation for the application of 3DP-7721 models in drug devel