摘要：连续-离散耦合方法同时集成了有限元和离散元的优点,在非连续介质边坡的破坏模式和机理研究中已得到一定应用,但是该方法不能定量分析边坡的稳定性。为了解决此问题,首先开发出一种连续-离散耦合强度折减法,提出了宏、细观强度折减系数关系的建立方法,然后基于某经典边坡算例验证了方法的可行性,并从细观角度上研究了边坡破坏机理和失稳判据,最后讨论了耦合强度折减法最优离散域的选取原则和方法。结果表明:宏、细观折减系数之间满足指数增长关系;从耦合计算位移连续性、边坡安全系数、潜在滑动面多个角度验证了连续-离散耦合强度折减法是可行的,安全系数较其他方法差距最大为5.39%;边坡临界破坏时拉力链数量和颗粒间黏结破坏数量会出现明显的突变,由此提出可将这2种细观上的突变作为新的边坡失稳判据;最优离散域的安全系数较标准值差距仅为0.02%;选取离散域时,应遵循充分发挥离散元优势、权衡数值计算效率、简化数值计算模型等原则,即尽可能穿过边坡潜在滑动面、减少离散域的大小、采用规则和简单的矩形。

摘要：职业教育现场工程师培养是中国特色学徒制的体现,本研究遵循“理论研究→生态体系模式逐级构建→实践验证与分析→优化与完善”的思路。通过文献研究分析国内外人才培养模式,进行调研访谈和分析比较,从企业岗位多层次人才需求和岗位调研入手,以实现分析检验技术现场工程师对岗精准培养、育训结合培养和职业生涯持续培养为核心目标。以“石化产品分析检验技术”专业教学改革为抓手,探索基于产科教融合的“园校企协同”共育人才的理论实现有效路径,逐级构建适应石化产业数智赋能型分析检验技术现场工程师培养的新生态、新体系和新模式。

摘要：移动通信和电子设备的普及促进了社会进步。然而，随之产生的电磁污染等问题严重降低信息传递的质量，同时损害生物体的健康。磁/介电复合材料凭借良好的电磁损耗和阻抗匹配展现出优异的电磁波吸收性能，已成为人们研究的重点。采用碳热还原法制备出3种磁纳米合金/石墨烯复合材料。结果表明，随着烧结温度提升，石墨烯缺陷密度的增加导致介电常数降低，而FeCoNi合金因其高饱和磁化强度展现出较高的磁导率，使复合材料的阻抗匹配得到优化。因此获得最小反射损耗值为-63.8 dB,有效吸收带宽为4.24 GHz的FeCoNi/石墨烯复合型吸波材料。此外，雷达散射截面结果表明，FeCoNi/石墨烯复合材料在模拟真实环境中具有良好的电磁衰减能力，因此该吸波材料有望在复杂电磁环境中得到应用。

摘要：物资关系图谱是电力企业物资管理精益化,所采取的一种新型技术工具。物资关系包含配套关系、数量关系和时效关系,为物资标准化体系提供多方面的知识支持。关系图谱绘制通常需要对样本进行降噪,以保证绘制结果的质量。本文设计了一种基于熵分析的降噪方法,可以实现无人工干预的数据清洗,解决了传统方法中过度依赖专家的问题。

摘要：Site-directed mutagenesis (SDM) has been a very important method to probe the function-structure relationship of proteins. In this study, we introduced an easy-to-use, polymerase chain reaction (PCR)-based SDM method for double-stranded plasmid DNA, with a designed restriction site to ensure simple and efficient mutant screening. The DNA sequence to be mutated was first translated into amino acid sequence and then the amino acid sequence was reversely translated into DNA sequence with degenerate codons, resulting in a large number of sequences with silent mutations, which contained various restriction endonu-clease (RE) sites. Certain mutated sequence with an appropriate RE site was selected as the target DNA sequence for designing a pair of mutation primers to amplify the full-length plasmid via inverse PCR. The amplified product was 5′-phosphorylated, cir-cularized, and transformed into an Escherichia coli host. The transformants were screened by digesting with the designed RE. This protocol uses only one pair of primers and only one PCR is conducted, without the need for hybridization with hazardous isotope for mutant screening or subcloning step.

摘要：Based on the lead compound 1 reported in literature, a series of novel BACE1 inhibitors were designed and synthesized, among which compound 11 exhibited a 14-fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD.

摘要：By taking compound 1 as a lead, a series of 5-cyclopropyl substituted cyclic acylguanidine compounds were designed and synthesized as BACE1 inhibitors, compound 4d exhibited 84-fold improved inhibition efficiency than lead compound 1. The diphenyl fragment at the P3 position and the substituents at the second phenyl ring were essential for the compounds to achieve improved inhibition efficiency. This SAR studies provides new insights into the design and synthesis of more promising BACE1 inhibitors for the potential treatment of AD.

摘要：Based on the lead compounds 1 and 2, a series of novel BACE1 inhibitors were designed and synthesized,among which compound 9h exhibited a 60 fold improvement in potency over the lead compound 1. This represents a good lead for the discovery of more promising BACE1 inhibitors for the potential treatment of AD. The result also showed that the prop-2-yn-1-yloxy is a suitable fragment for modification of cyclic acylguanidine BACE1 inhibitors.

摘要：提出面向机会社会网络的服务广告分发机制,解决移动网络环境中由于节点移动性、拓扑动态性引起的集中式服务注册库失效的问题.首先分析机会社会网络中服务表现出的社会特征,提出服务社会上下文及其参数度量方法;然后提出基于社会上下文的服务广告分发机制,该机制根据服务行业相关度判断用户对服务的感兴趣程度,以确定广告目标节点,根据可靠度和活跃度计算节点效用,并根据行业时空共存关系预测节点和服务行业相遇概率,以动态选择服务广告代理;最后在社区移动模型下进行了仿真实验,验证了算法的正确性和有效性.

摘要：封隔器卡瓦作为井下作业中关键的锚定部件,其性能直接影响井下作业的安全性和效率。本文系统分析了卡瓦几何参数对接触面积、接触应力和剪切应力的影响规律,提出通过优化几何参数(包括牙数、牙顶角、牙倾角、圆心角和咬入深度)提高卡瓦锚定性能的策略。研究采用有限元仿真并结合理论建模,发现增加牙数和咬入深度能显著提升接触面积并降低接触应力;而适当控制牙顶角和牙倾角则有助于降低局部应力集中现象,延长卡瓦的使用寿命。本文的研究成果不仅为封隔器卡瓦的优化设计提供了理论依据和数据支持,还对井下复杂环境中的锚定技术创新具有重要指导意义。