摘要：The phase relationships in the Zn-Al-Ti system at 450 and 600℃ were experimentally determined using equilibrated alloys *** specimens were investigated by means of scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray *** and eight three-phase regions are confirmed in the 450 and 600℃ isothermal sections,*** Ti2Al5 which only exists at high temperature(990-1199.4℃)in Ti-Al binary system is confirmed in two isothermal sections due to the dissolution of *** T phase is confirmed as a ternary compound rather than an extension phase of TiZn3 at 450℃.The T2 phase is a new ternary phase stable at 450 and 600℃ in Zn-Al-Ti ternary system.

摘要：研究一种动态协同和声搜索算法,并对无线传感器网络的覆盖感知模型进行求解.该算法设计多种群动态协同进化策略,改善和声搜索算法的多样性.在和声记忆库考虑阶段,引入轮盘赌选择,提高搜索的有效性.同时,对算法参数进行动态调节,以提高算法的优化性能.无线传感器网络覆盖优化问题的优化仿真结果表明所提算法取得较优的结果.

摘要：液体晃荡砰击载荷是液化天然气(LNG)运载装备液舱结构设计的关键载荷之一。液体晃荡砰击载荷过大时,会导致液舱结构产生局部破坏,进而导致液舱内液体泄露,甚至船体倾覆。基于前期数值结果,本文设计了梯形体和正方体两种壁面结构,开展了不同壁面结构下的液体晃荡砰击试验。针对自由液面演化过程以及液体晃荡砰击载荷分布特性,结合统计分析方法,定性和定量地分析了壁面结构对液体晃荡砰击的抑制效果。研究结果表明,壁面结构的存在改变了液体晃荡砰击过程中的流场分布,使砰击由液体直接砰击改变为裹气液体的间接砰击。裹气液体晃荡砰击过程中产生了大量气液混合物和气泡,从而有效地降低了砰击载荷,并且正方体结构抑制砰击载荷的效果优于梯形体结构。

摘要：大规格闸阀有低流阻、高可靠性以及使用周期长等特点,被广泛应用于矿山、冶金和石油等行业。但大规格闸阀的主阀体内腔较大,且截面形状不规则,根据传统设计方法难以精确计算强度,导致阀门设计过于保守,造成成本高、效率低等缺陷。本文利用CAD技术对大规格楔形闸阀进行改良,提高材料成本合理化布局,简化制造和装配,提高了工作效率。通过ANSYS有限元分析和Autodesk Inventor三维建模等方式,可以使优化后阀体和闸板应力分别减少4.26%和15.83%,显著降低阀门重量和成本,为大规格阀门设计提供参考。

摘要：水下闸阀是水下生产系统的关键,其稳定性和安全性对油田安全至关重要。针对国内海洋天然气工业水下阀门技术瓶颈,本文提出一种新型水下闸阀方案,适用于深水环境。设计强调动作可靠性,基于液压执行机构,引入独立螺旋传动执行机构作为应急方案,确保液压故障时能迅速切换,保障闸阀持续运行。同时,深入分析和验证了闸阀的密封性能,确保高压环境下的密封性。开发的阀门控制系统采用西门子PLC和相关软件编写控制程序,实现精确控制。液压故障时,系统自动切换至螺旋传动执行机构,确保操作的连续性和可靠性。

摘要：A comprehensive understanding of excited-state dynamics of semiconductor quantum dots or nanomaterials at the atomic or molecular level is of scientific *** inorganic(or non-covalently protected)seimiconductor molecular nanoclusters with atomically precise structure are contributive to establish accurate correlation of excited-state dynamics with their composition/structure,however,the related studies are almost blank because of unresolved solvent dispersion ***,we designedly created the largest discrete chalcogenide seimiconductor molecular nanoclusters(denoted P2-CuMSnS,M=In or/and Ga)with great dispersibility,and revealed an interesting intracluster“core–shell”charge transfer relaxation dynamics.A systematic red shift in absorption spectra with the gradual substitution of In by Ga was experimentally and computationally investigated,and femtosecond transient absorption measurements further manifested there were three ultrafast processes in excited-state dynamics of P2 nanoclusters with the corresponding amplitudes directed by composition *** results hold the great promise of the solution-processible applications of semiconductor-NC-based quantum dots and facilitate the development of atomically precise nano-chemistry.

摘要：目的以石库门地域文化为研究对象,探索地域文化特征应用于导视系统设计的创新方法。方法收集石库门样本图片,用R语言进行聚类分析,筛选出典型样本。运用语义差异法获取石库门风格意象,采用层次分析法进行石库门设计因子的层次模型构建,从造型、色彩、材质3个方面进行设计因子的提取,搭建层次分析矩阵,计算设计因子的重要性,从而指导导视系统的设计。通过风格意象评价进行导视系统方案的筛选。结果根据语义差异法和层次分析法,获取石库门地域文化的风格意象和设计因子,并将其应用于老码头创意园导视系统设计。结论通过石库门风格意象和设计因子的提取方法,提升导视系统和地域文化的融合性,既能为导视系统的创新设计提供动力,又能提升场所的文化气氛,为文化传承指引方向。

摘要：将顶空平衡法与配置脉冲氦离子化检测器的气相色谱仪相结合,自主设计并优化建立了适用于水中溶解氢气(H_(2))浓度测定的自动化观测系统和方法.测试结果表明,该观测系统对H_(2)摩尔比范围为550.2×10^(−9)—4000×10^(−9)标气的线性优于0.9995(R^(2)),精密度优于0.07%,准确度优于1.09%,重复性测试结果优于世界气象组织/全球大气观测网的质控要求.基于亨利定律和道尔顿分压定律,推导了更简便实用的溶解H_(2)浓度计算公式.基于该观测系统和方法,于2022年8月开展了京杭运河杭州段溶解H_(2)浓度及水-气H_(2)交换通量的观测研究.结果显示,京杭运河杭州段溶解H_(2)浓度和水-气H_(2)通量的范围分别为216.9—409.4 nmol·L^(−1)和172.1—20513.1μmol·(m^(2)·d)^(−1),是大气H_(2)净排放源,且城区比乡村河段的溶解H_(2)浓度平均高29.6 nmol·L^(−1),表明人为活动是影响淡水系统H_(2)源强和排放量的重要因素之一.

摘要：A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.

摘要：10-kV 4 H–SiC p-channel insulated gate bipolar transistors(IGBTs) are designed, fabricated, and characterized in this paper. The IGBTs have an active area of 2.25 mm^2 with a die size of 3 mm× 3 mm. A step space modulated junction termination extension(SSM-JTE) structure is introduced and fabricated to improve the blocking performance of the *** SiC p-channel IGBTs with SSM-JTE termination exhibit a leakage current of only 50 nA at-10 kV. To improve the on-state characteristics of SiC IGBTs, the hexagonal cell(H-cell) structure is designed and compared with the conventional interdigital cell(I-cell) structure. At an on-state current of 50 A/cm^2, the voltage drops of I-cell IGBT and H-cell IGBT are10.1 V and 8.3 V respectively. Meanwhile, on the assumption that the package power density is 300 W/cm^2, the maximum permissible current densities of the I-cell IGBT and H-cell IGBT are determined to be 34.2 A/cm^2 and 38.9 A/cm^2 with forward voltage drops of 8.8 V and 7.8 V, respectively. The differential specific on-resistance of I-cell structure and H-cell structure IGBT are 72.36 m?·cm^2 and 56.92 m?·cm^2, respectively. These results demonstrate that H-cell structure silicon carbide IGBT with SSM-JTE is a promising candidate for high power applications.