摘要：目前用于光学设计的计算机辅助设计有许多种,但它们在像差特性参数的形式和表示方法上不尽相同,特别是国内外软件的这种差别更为明显,例如:ZEMAX将球差表示为“Long itud inal aberration”(纵向像差),其表示形式也与国内软件不同。另外,有些像差参数需要转换。采用美国焦点软件公司开发的光学设计软件ZEMAX和国内北京理工大学编写的DOS版CAOD对同一双胶合透镜进行光路计算,同时对其轴上球差、彗差、场曲和畸变等主要几何像差在2个软件之间的差别进行比较,以建立国内软件与国外软件在进行光学镜头设计时的光学像差特性参数的转换关系,并为光学设计者提供设计一种镜头或光学系统时使用不同的软件进行数据核查和复算的方法。

摘要：针对自动驾驶场景下交通目标检测算法存在的误检及漏检的问题,提出一种基于改进YOLOv8s模型的复杂道路交通目标检测算法。设计一种轻量级的C2f⁃EMSCP模块改进YOLOv8s的骨干网络,实现网络的参数量和计算量的降低;在Backbone和Neck部分添加EMA注意力模块,有效地捕捉了全局的通道依赖性与局部空间特征,实现在通道和空间维度上的全面特征抽取;针对密集车流下小尺寸车辆检测效果不佳的问题,添加小目标检测头,更好地捕获小尺寸车辆的特征和上下文信息;使用可自适应调整权重系数的Wise⁃SIoU作为改进模型的损失函数,提升了边界框的回归性能和检测的鲁棒性。在KITTI数据集上进行实验,P、R和mAP@0.5分别提高了0.4%、2.1%和3.7%。文中的改进方法在交通监控系统中能够达到较好的检测精度和速度,有效改善了复杂交通场景下小目标车辆检测效果不佳的问题。

摘要：Fe/N/C material is the most competitive alternative to precious-metal catalysts for oxygen *** view of the present consensus on active centers,further effort is directed at maximizing the density of single Fe ***,the imperfections in commonly used doping strategy of Fe for the synthesis of zeolitic imidazolateframework(ZIF)-derived Fe/N/C catalysts are *** importantly,a strikingly improved catalyst is obtained by a‘second pyrolysis’method and delivers a half-wave potential of 0.825 V(***)in acidic *** strong confinement effect of carbonaceous host accounts for the formation of dense single-atom sites and thus the high *** findings will potentially facilitate future improvement of M/N/C catalysts.

摘要：The ability to expand genetic code in living cells has emerged as a powerful method with diverse ***,we design re-placement of the anticodons of *** tRNAs that recognize codons for 20 natural amino acids,with three anti-stop codons,resulting in a total of 60 engineered tRNA *** test these constructs one by one in ***,and found that six tRNAsCUA(tyrV,serX,hisR,trpT,glnV and leuX),two tRNAsUCA(trpT and leuX)and one tRNAUUA(tyrV)allowed efficient expression of Red Fluorescence Protein(RFP)with the presence of a corresponding stop codon in ***,we exploit the mutual orthogonality of tRNASer CUA,tRNATrpUCA and tRNATyrUUA with corresponding stop codons and demonstrated that the tRNASer CUA and the tRNATrp UCA can provide dynamic range and low ***,we show the TAG and TGA can not only be used as an"AND gate"circuit to control the translation of target gene,but also be used to control the translation of a prodeoxyviolacein(PDV)pathway and a reporter in ***,this work provides flexible tools for translational control and holds great potential to promote synthetic biology studies.

摘要：三种稠油测定结果表明,稠油黏度与其自身胶质含量密切相关。合成了两种新型降黏剂,即降黏剂1(VR-1)和降黏剂2(VR-2),该新型降黏剂对新疆稠油表现出较好的降黏效果,且后者的降黏效果优于前者。紫外-可见结果表明,与VR-1相比,VR-2对胶质的分离效果更好,这可能与降黏剂VR-2与胶质分子形成更强氢键作用来分散了胶质聚集体并改变了其原始的致密结构有关,红外测定结果表明胶质分子中含有较多的杂原子和极性基团,为氢键的形成提供有利条件。综上,两种降黏剂对稠油中的胶质具有不同作用的原因得到解释。

摘要：Physical forces,such as magnetic and mechanical stimulation,are known to play a significant role in the regulation of cell *** the present study,a biomimetic regeneration patch was fabricated using E-jet 3 D printing,which integrates mechanical and magnetic stimulation in a biocompatible"one-pot reaction"strategy when combined with a static magnetic field(SMF).The magneto-based therapeutic regeneration patch induced myoblasts to form aligned and multinucleated myotubes,regulated the expression of myogenic-related genes,and activated the p38αmitogen-activated protein kinase pathway via the initiation of myogenic *** validate the efficiency of the proposed strategy,the regeneration patch was implanted into mice and exposed to a suitable SMF,which resulted in significantly enhanced in vivo skeletal muscle *** findings demonstrated that appropriate external physical stimulation provides a suitable biophysical microenvironment that is conducive to tissue *** method used in the present study represents a promising technique to induce the regeneration of damaged skeletal muscle tis sue.

摘要：电线积冰是一种普遍的自然现象,输电线路覆冰后可能会引起线路断裂、冰闪跳闸等电力灾害从而影响正常的生产生活,准确及时观测并发布电线积冰情况对保障电网正常运行具有重要意义。基于称重法原理设计的电线积冰自动观测系统,使用无迹卡尔曼滤波方法对系统观测数据进行滤波处理并与扩展卡尔曼滤波方法进行滤波效果对比评估。结果表明,无迹卡尔曼滤波算法在原始称重数据降噪中有着良好效果,其滤波效果优于扩展卡尔曼滤波方法。

摘要：【目的】为提高熔融沉积(fused deposition modeling,FDM)型3D打印机喷头温度控制中的精度和稳定性,提出了基于深度确定策略梯度(deep deterministic policy gradient,DDPG)算法的温度控制策略。【方法】首先,对3D打印机打印喷头进行数学建模;然后,在设计基于DDPG算法的马尔科夫决策过程(markov decision process,MDP)模型时,以目标温度、当前温度和时间作为状态观测变量,以比例积分微分(proportion integral differential,PID)控制器的3个参数作为输出动作值,设置多个全连接隐藏层来捕捉复杂非线性关系,并基于温度偏差设计了一组复合型奖励函数;最后,搭建仿真模型对算法进行了验证。【结果】与传统PID和模糊PID控制策略相比,基于DDPG的PID响应时间分别缩短了37.01%和18.36%,调节时间分别缩短了27.14%和8.91%,超调量分别降低了74.14%和58.89%。【结论】本方法显著提升了FDM型3D打印机喷头温度控制系统性能,可为3D打印喷头温度控制精度和稳定性研究提供参考。

摘要：该文涉及一种耐高污染直动式电液伺服阀的驱动装置,属于机电一体化范畴的电动―液压自动控制系统领域。耐高污染电液伺服阀具有响应速度快,不会堵塞,坚固耐用的特点。该文从贴近实际使用角度出发介绍了一种全新设计的、简化的直线驱动装置的机械和电器结构。

摘要：Near infrared(NIR) absorbing and emitting dyes are sought after for their potentials in bioimaging and theranostic applications. They are typically not as stable as dyes absorbing and emitting in the visible spectral range, as the result of a reduced HOMO-LUMO band-gap. Also, they are not as efficient fluorescence emitters due to accelerated internal conversion kinetics. In addition, their large conjugative backbone render them high tendency to form aggregate and low aqueous solubility. In this tutorial, we have described a four-step approach for rational design of organic dyes with an overall high-performance to meet the rigorous requirements of biological applications. Also, some background regarding "NIR" is provided along with some recent breakthroughs of the field.