摘要：为解决天基特征光谱最佳探测波段的选择问题，以11种导弹尾焰在2．5～5μm处的光谱作为研究对象，综合考虑导弹距地面高度、大气传输、云层辐射、大气辐射等因素，设计出一种从多目标角度考虑的波段选择算法，以目标相对具有强辐射为原则，根据距地面高到低、波段从多到少的顺序进行选择，可通过设定阈值来控制所选波段个数，文中所选波段的中心波长分别为2．99、3．06、3．12、4．6、4．62μm。根据光谱图像拟合规则拟合出包含目标的特征光谱图像，从信噪比的角度对特征光谱图像和全波长图像进行分析，结果表明，当目标达到一定高度后，特征光谱图像的信噪比远大于全波长图像。

摘要：目的:研究多准则约束下的产品模块划分方法,为企业建立稳健的模块化产品平台奠定基础。方法:采用改进的多目标进化算法对建立的多准则模块划分数学模型求解,并采用模糊集合评价机制进行最优解的寻取,得到基于多准则模块划分方法的产品模块划分结果。结论:通过改进的多目标进化算法求解多准则模块划分模型,能够得到有效支持产品平台设计的产品模块划分方案。通过与已有优化方法的比较验证了本文提出的多准则模块划分方法的优越性。

摘要：目的评估因严重呼吸系统疾病行有创机械通气(invasive mechanical ventilation,IMV)治疗儿童PICU住院后的神经发育和精神障碍情况。设计回顾性纵向观察性队列研究。场所德克萨斯州医疗补助计划1999至2012年的提取数据。对象德克萨斯州医疗补助计划纳入的因原发呼吸系统疾病住院,且无可能导致神经发育异常的重大慢性疾病的28 d~18岁患儿。干预措施本文研究因严重呼吸系统疾病需要IMV儿童出院后ICD-9编码的精神障碍疾病诊断率和精神病药物使用率,并与入院前社会人口学和临床特征倾向性评分匹配的普通病房住院患儿进行比较。

摘要：5.未来方向的建议 5.1集成工艺过程设计的框架 仅仅在逻辑上期望制造工艺设计应该它自己本身的集成,这集成的目标是针对产品设计和制造人工智能和集成工艺将成为计算机集成制造的范例,并且是从现行的信息密集时代到将来的知识密集时代工业发展的关键推动力量。 当讨论产品设计和制造集成或集成工艺设计时,其中一个很重要的问题就是要理解“集成”的真正意义和复杂性。现在在集成和接口(Lnterfacing)之间存在着模糊概念。有很多方法去集成产品设计和制造或各种工艺设计功能,反过来亦是这样。但是仔细检查这些方法表明它们试图把产品设计,制造及工艺设计的各种分离活动用接口连起来。

摘要：这篇论文探讨了对计算机集成制造系统(CIMS)有重要意义的计算机辅助工艺过程设计(CAPP)研究工作的目前状况和将来发展方向。本文不讨论CAPP的某一方面的问题,也不讨论某一具体原形系统的细节,而主要重点是讨论为各种制造任务而开发的以计算机为基础的工艺设计的全面性的基本展望。为了回顾一下当前的研究状况,本文参考了1987年6月1～2日在美国宾州大学召开的第19届CIRP(国际生产工程研究协会)主题为计算机辅助工艺过程设计生产系统国际研讨会中的学术论文。在提出将来方向上,建议一个集成设计框架作为现行的CAPP活动的逻辑扩展。文中对制造问题的这种集成设计方法的重要性和挑战性进行了归纳,并特别对这种框架中的以人工智能(AI)为基础的重要意义进行了论述。这篇论文的目的在于通过对未来无人化生产为最终目标所做的各种努力进行评论,促进人们更好地理解与生产有关的工艺设计工作的性质和潜力。

摘要：In order to solve the serious problems of seeds are covered by residual film and overhead by straw during no-till seeding,a seed furrow cleaning device for no-till maize seeding was developed,which adopted a collaborative cleaning method of rotating spring teeth and curved sliding *** movement process and motion trajectory of throwing residual film and straw were *** maximum distance of throwing to one side in horizontal and maximum height in vertical were *** motion trajectory of adjacent spring teeth was analyzed by Matlab,the motion trajectories of adjacent spring teeth at different speeds of 120 r/min,150 r/min and 180 r/min were achieved,the theoretical analysis results showed that the area of omitted area decreased with the increase of rotation *** on theoretical and simulation analysis of critical parameters,the forward speed of machine,rotation speed of spring teeth,and dip angle between spring teeth and rotary disc were selected as the influencing *** cleaning rate(SCR)and residual film cleaning rate(RFCR)were selected as the response values for three factors and three levels of orthogonal experiment *** optimal combination of the selected parameters was obtained,and the field test verification was also *** results showed that the rotation speed of spring teeth,forward speed and dip angle of spring teeth significantly affect SCR and RFCR were in decreasing *** field test results indicated that when forward speed was 6 km/h,rotation speed of spring teeth was 180 r/min and dip angle of spring teeth was 40°,SCR and RFCR were 88.27%and 84.31%,*** study provides a reference for the development of no-till seeder in Xinjiang and the northwestern regions of China.

摘要：全国重点文物保护单位是中国对于不可移动文物所核定的最高保护级别,具有极高的历史、艺术和科学价值。基于国务院1961、1982、1988、1996、2001、2006、2013和2019年先后八次发布的5058处全国重点文物保护单位名单,利用百度地图服务接口提取各重点文物保护单位地理坐标,获得全国重点文物保护单位的空间分布数据集。该数据集包括每个国保单位的名称、编号、分类号、时代、文物类别、批次和地址等信息。数据集以.shp和.xls格式存储,由8个数据文件组成,数据量为25.8 MB(压缩为1个文件,839 KB)。

摘要：采用“弯矩逐段解体法”沿建筑物的对角线方向爆破的方法 ,成功地拆除了一栋七层框架结构大楼。文中对沿对角线方向倾倒与平行于梁的方向倾倒的受力情况进行了对比 ,并对沿对角线方向倾倒时梁的受力情况进行了详细分析。此外 ,对爆破参数和网路设计以及安全技术作了论述。

摘要：The development of low-cost,highly active platinum(Pt)-based electrocatalysts for oxygen reduction reaction(ORR)is crucial for widespread applications of fuel *** effective approach lies in alloying Pt with non-noble transition metals to modulate the physicochemical state of the Pt ***,fundamental challenges remain in understanding the structure-performance relationship due to the complexity of composition,crystal type,and surface structure during the alloying *** this study,we synthesized a series of PtCo bimetallic solid solutions with varying ratios using a liquid-phase synthesis *** exploiting the characteristics of solid solutions,the resulting PtCo bimetallic alloy maintains the face-centered cubic crystal structure of pure platinum,minimizing the complexities introduced during alloying and facilitating mechanism ***,under controlled alloy composition and crystal structure,we investigated the dependence of the electrocatalytic activity for the oxygen reduction reaction on the surface strain of the platinum *** S-PtCo-SNPs cathode designed accordingly endows both proton exchange membrane fuel cell(PEMFC)(2.08 W cm^(−2) at 4 A cm^(−2))and Zn-air battery(ZAB)(143.1 mW cm^(−2) at 214.5 mA cm^(−2))with outstanding performance.

摘要：Introduction 3D bioprinting offers a unique biofabrication platform that allows the generation of functional tissue constructs in a spatially/geometrically controlled and automated manner using a 3 D printer and *** serves as the carrier medium that provides the ideal physico-mechanical characteristics for printability,shape fidelity,and support;and a biological microenvironment for the living cells prior to,during.