摘要：随着自然语言处理技术的不断创新,自动文摘的质量得到显著提高。面向科技成果文档的中文自动文摘成为研究热点,具有一定的应用价值。把聚类算法应用到自动文摘中,选取聚类中心的思想对文摘去冗余具有一定意义。结合密度峰值算法,设计实现了面向科技成果文档的中文自动文摘系统。实验结果表明:应用密度峰值算法有利于文摘的冗余处理,具有借鉴意义。

摘要：非物质文化遗产的保护与传承一直是地方政府的重要关注点。青岛市不断探寻将非物质文化遗产与旅游产业、影视动漫产业、节庆产业、展览产业等融合互动发展之路径,借助于"互联网+"打造以非物质文化遗产为内容资源的文化创意产业发展新模式。这种模式的创建既使非物质文化遗产能够得以有效的保护与传承,也为青岛市地方经济的发展提供新的着力点和增长点,从而实现青岛文化的大发展和大繁荣。

摘要：由于传统公开密码技术很难在资源受限的水电厂系统智能终端上部署,智能终端的安全数据传输成为水电厂信息系统亟需解决的问题。为此,文章提出一种基于网络水印的轻量级安全通信方法。首先,发送端通过水印嵌入算法将标识该终端的身份信息以水印的方式嵌入到网络包中,接收端通过水印提取算法提取出网络水印,这样不但可以认证发送端的合法性,还可以生成通信会话密码。其次,利用由网络水印生成的密钥,结合国产密码技术SM4,设计了基于双向身份认证的安全数据传输模型。实验结果表明,所提可信智能终端安全通信方法不但可以通过认证智能终端身份提高数据传输的安全性,也可以提高数据加密的效率。

摘要：A small prototype of an active-target time projection chamber detector based on the gas electron multiplier(GEM) readout technique was designed and *** calculations were performed to analyze the electric field distribution and optimize the *** particular,a guard ring installed above the GEM foil may play an important role in shaping the electric field in the gas vessel and improving the overall performance of the *** best results were obtained at a guard-ring voltage of-950 *** using a collimated a-particle source,an energy resolution of 3.6–4.0 ke V can be achieved for deposited energies of 18–21 keV,respectively.A position resolution of less 0.2 mm was observed along the electron drift direction,whereas the resolution in the readout plane was approximately 0.45 mm.A time resolution of less than 20 ns was *** using helium as the primary working gas as well as the target material,a t a elastic scattering events can be clearly imaged.

摘要：为解决繁琐的计算制约着可靠度优化设计方法应用于桩基工程这一问题,分析了竖向荷载下基桩的破坏模式,利用可靠度理论和优化设计方法建立了可靠度优化设计模型.基于中心点法,提出了一种改进的可靠度优化计算方法,用以解决可靠度优化计算中产生的非线性迭代繁琐过程.建立了可靠度指标的修正函数以提高计算精度,并利用线性回归方法给出了修正函数的计算方法.实例分析结果表明:改进的可靠度优化方法在提高计算效率的同时也保证了计算精度;局部优化和全局优化后的目标函数值分别减小了20.2%和24.9%,较大程度地降低了施工成本.

摘要：An experiment was conducted to investigate the requirement of nonphytate phosphorus（nPP） and efficacy of a genetically engineered yeast phytase（PHY A） for Lingnan yellow broilers from 22-to 42-d-old age.A total of 1 320 1-d-old male chicks were randomly divided into 11 dietary treatment groups,which consisted of 4 replicate floor pens with 30 birds per *** control group（treatment 1） was fed with basal diet of nPP 0.08% without dicalcium phosphate or phytase *** levels of nPP were 0.16,0.24,0.32,0.40,0.48,and 0.56%,respectively,for treatments 2 to 7,through addition of dicalcium phosphate（chemistry grade） to the basal *** of treatments 8 to 11 were supplemented with PHY A at 200,400 and 600 U kg-1,a commercial phytase product（PHY B） at 400 U kg-1 level,*** birds in 0.32-0.56% nPP groups gained more than those of the other groups（P0.05）.The nPP supplementation significantly improved feed intake（P0.05）.The feed gain ratio was significantly decreased by 0.40% nPP diet compared to the control birds（P0.05）.The level of 0.48% nPP was required for optimum tibia *** additions of PHY A at 400 and 600 U kg-1 level and PHY B all significantly improved ADG（P0.05）,ADFI（P0.05）,and dry defatted tibia weight（P0.05）.Similarly,the percentage of tibia ash was increased by 600 U kg-1 PHY A supplementation（P0.05）.The requirement of nPP for maximal ADG and highest percentage tibia ash both was 0.40%.The phosphorus equivalency value of PHY A was estimated as 685 U kg-1 for male yellow broilers of 22-to 42-d-old age.

摘要：利用APDL语言,基于标准齿轮的齿廓渐开线方程和齿根过渡曲线方程,建立某型号减速器精确参数化三维有限元模型。基于接触碰撞算法运用显式动力学程序ANSYS/LS-DYNA在工作站上对整体齿轮箱工作过程进行了仿真计算,准确地得到了齿轮箱内部的应力应变情况以及动态接触过程中的压力分布情况。并将计算结果与传统赫兹理论计算结果进行了比较,验证了该方法的合理性。该方法能从系统的层面,综合考虑齿轮箱各零件动态特性以及相互作用,从而实现对齿轮箱动态特性进行精确的预测和评估。在此基础上考虑各种原始制造误差对齿轮箱动态性能的影响,为齿轮箱整体动态优化设计提供可靠的理论依据。

摘要：激光制导是当今最常用的制导方式之一,激光半主动光学系统性能的优劣直接影响其制导精度。提出了一种激光半主动光学系统像差优化设计方法,通过赋予不同的球差与离焦量实现激光半主动光学系统初始结构设计,通过对非对称像差优化实现光斑均匀化设计,设计并研制了折射式激光半主动光学镜头,光学系统工作波段1 064 nm,视场为±9.2°,光斑大小5 mm,能量分布均匀;为解决激光半主动镜头不能单独检测的问题,提出了利用色差特性实现镜头低成本可视化检测的原理,并搭建了激光半主动光学镜头的可视化检测系统。镜头的测试结果表明,光斑大小满足设计要求,低成本可视化检测系统大幅提高了镜头检测效率,并易于工程化,批量化生产。

摘要：提出了一种融合新型支撑方式与灵敏度分析的光机热集成分析与优化方法,用于设计超高精度深紫外光刻投影物镜系统。首先,采用轴向多点与周向三点胶接支撑相结合的新型支撑方式,实现了212.51 mm口径光学元件的超高精度定位要求。其次,通过对光学元件进行热力耦合分析,验证了光机系统的合理性。然后,在光机热集成分析条件下,分析了单个光学元件的灵敏度,以及全部光学元件表面变形对整体光学系统波像差均方根值和校准F-tanθ(F为焦距,θ为物方视场角)畸变的影响。最后,通过调整部分光学元件的灵敏度进行局部优化,并对整体光学系统的像质进行优化。结果表明:在热力耦合条件(参考温度为22.5℃、极限工作温度为±2.5℃、重力)下,光学元件的最大表面面型均方根(RMS)值为9.86 nm,能够满足超高精度定位要求。在光机热集成分析条件下(参考温度为22.5℃、极限工作温度为±2℃、重力),优化后光学系统的波像差RMS值小于10.50 nm,校准F-tanθ畸变小于6.00 nm,相较于优化前,波像差RMS提升了46.98%,校准F-tanθ畸变提升了77.69%,达到了设计要求。

摘要：A novel spiral non-circular bevel gear that could be applied to variable-speed driving in intersecting axes was proposed by combining the design principles of non-circular bevel gears and the manufacturing principles of face-milling spiral bevel *** straight non-circular bevel gears,spiral non-circular bevel gears have numerous advantages,such as a high contact ratio,high intensity,good dynamic performance,and an adjustable contact *** addition,while manufacturing straight non-circular bevel gears is difficult,spiral non-circular bevel gears can be efficiently and precisely fabricated with a 6-axis bevel gear cutting ***,the generating principles of spiral non-circular bevel gears were ***,a mathematical model,including a generating tooth profile,tooth spiral,pressure angle,and generated tooth profile for this gear type was *** the precision of the model was verified by a tooth contact analysis using FEA,and the contact patterns and stress distributions of the spiral non-circular bevel gears were investigated.