排序方式: 共有298条查询结果,搜索用时 15 毫秒
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基于先进逻辑CMOS工艺平台,构建了集成电路热耦合模型,为后端金属线电迁移预测提供更精确的温度变化和分布信息。在建模过程中,为了提高建模和仿真效率,对金属线网络和晶体管有源区进行简化,并用热传输比率对热耦合进行表征。考虑到晶体管参数、金属线走向、金属线之间相对位置对热传输比率的影响,模型中引入相关因子对热传输比率做进一步修正。最后,将该热传输模型嵌入到商用仿真软件中。结果表明,热传输比率(即温度)的仿真值与基于工艺平台流片的实测值吻合良好,验证了模型的准确性。 相似文献
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Additive Manufacturing (AM) requires integrated networking, embedded controls and cloud computing technologies to increase their efficiency and resource utilisation. However, currently there is no readily applicable system that can be used for cloud-based AM. The objective of this research is to develop a framework for designing a cyber additive manufacturing system that integrates an expert system with Internet of Things (IoT). An Artificial Neural Network (ANN) based expert system was implemented to classify input part designs based on CAD data and user inputs. Three ANN algorithms were trained on a knowledge base to identify optimal AM processes for different part designs. A two-stage model was used to enhance the prediction accuracy above 90% by increasing the number of input factors and datasets. A cyber interface was developed to query AM machine availability and resource capability using a Node-RED IoT device simulator. The dynamic AM machine identification system developed using an application programme interface (API) that integrates inputs from the smart algorithm and IoT interface for real-time predictions. This research establishes a foundation for the development of a cyber additive design for manufacturing system which can dynamically allocate digital designs to different AM techniques over the cyber network. 相似文献
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并行化程序运行环境中资源竞争导致的竞态漏洞是当今操作系统安全的重要威胁之一,攻击者常常间接利用竞态漏洞实施诸如远程命令执行、本地提权等攻击行为。分析了不同条件下竞态漏洞的产生机理及其相互关系,提出了竞态漏洞检测基本范式和通用框架,分别综述了用户态和内核态竞态漏洞检测方法的技术思想和发展脉络,讨论了制约检测效率的瓶颈问题以及可能的解决方法,结合最新技术应用指出了未来发展趋势和亟待解决的问题。 相似文献
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Liang Xu Tianyang Lei Boyu Jing Fengjuan Miao Toshiki Aoki 《Designed Monomers and Polymers》2018,21(1):99-104
Three soluble hyperbranched polyazomethines containing oligosiloxane end group HBP-PAZ-SiOn were successfully synthesized. HBP-PAZ-SiOns were used as modifiers of ethyl cellulose (EC) and polysulfone (PS) membranes. Blend membranes, HBP-PAZ-SiOn/EC and HBP-PAZ-SiOn/PS were prepared by blending the THF solution of HBP-PAZ-SiOn with ethanol solution of EC and dichloromethane solution of PS, respectively. Surprisingly, the permeabilities for CO2 of the blend membranes were more than 15–16 times higher than those of pure EC and PS membranes without any drop of pemselectivity to N2. This unusual improvement has been achieved by both enhancement of diffusivity for carbon dioxide and nitrogen by the oligosiloxane groups and enhancement of affinity of the amino groups with carbon dioxide at the end groups of HBP-PAZ-SiOn. 相似文献
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随机产生失效核分布的方法不能反映众核处理器物理拓扑结构的真实状况,在评价相关拓扑重构算法的效能时有失客观性.本文针对这一现状,提出了一种基于缺陷成团效应的众核处理器失效核分布建模方法.实验表明,本方法得到的物理拓扑结构缺陷分布呈现出不同程度的成团特性,且成团效应会显著影响核级冗余技术的拓扑重构效果. 相似文献
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过渡金属Fe2+是最经济有效且环境友好的PS活化物质,但是Fe2+易于被氧化而失去活化能力导致Fe2+/PS体系持续效果较差。为了提高Fe2+活化PS氧化降解有机污染物的效率,本论文将医学上常用的碘化X射线显影剂(ICM)的典型代表碘海醇(Iohexol)作为目标污染物,研究其在UV/PS、Fe(C2O4)33-/PS、UV/Fe(C2O4)33-/PS和Fe2+/PS 4种高级氧化体系中的降解,考查Fe(C2O4 )33-浓度、紫外光强和pH对UV/Fe(C2O4)33-/PS体系中碘海醇降解和PS活化分解的影响,并且分析体系中Fe2+浓度变化及其转化率。结果表明:4种高级氧化体系中碘海醇的氧化分解率分别为:83.8%、7.0%、98.8%、69.9%,其中,UV/Fe(C2O4 )33-/PS体系能够通过紫外光促进铁离子还原,溶液中对PS起活化作用的Fe2+逐渐释出,对碘海醇的降解最为高效彻底。随着Fe(C2O4 )33-浓度的增加,UV/Fe(C2O4 )33-/PS体系中PS的分解率不断增加,而碘海醇的降解率却先增加后减少。4种不同初始Fe(C2O4 )33-浓度下(20 μM、50 μM、100 μM、200 μM),碘海醇降解速率依次为:100 μM > 200 μM > 50 μM > 20 μM。在UV/Fe(C2O4 )33-/PS体系中,Fe2+浓度均是先快速增加后缓慢下降,碘海醇的降解率、PS的分解率以及Fe2+的最高转化率均与光强正相关,与pH负相关。因此,利用紫外光还原铁离子能够极大的提高提高Fe2+活化PS效率,且体系对于光强、pH等影响因素有较强的适应能力,在水处理高级氧化领域的具有较大的应用前景。 相似文献
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Sha Bai Ling Tan Chenjun Ning Guihao Liu Zhaohui Wu Tianyang Shen Lirong Zheng Yu-Fei Song 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(21):2300581
Electrocatalytic reduction of CO2 to high-value-added chemicals provides a feasible path for global carbon balance. Herein, the fabrication of NiNPx@NiSAy-NG (x,y = 1, 2, 3; NG = nitrogen-doped graphite) is reported, in which Ni single atom sites (NiSA) and Ni nanoparticles (NiNP) coexist. These NiNPx@NiSAy-NG presented a volcano-like trend for maximum CO Faradaic efficiency (FECO) with the highest point at NiNP2@NiSA2-NG in CO2RR. NiNP2@NiSA2-NG exhibited ≈98% of maximum FECO and a large current density of −264 mA cm−2 at −0.98 V (vs. RHE) in the flow cell. In situ experiment and density functional theory (DFT) calculations confirmed that the proper content of NiSA and NiNP balanced kinetic between proton-feeding and CO2 hydrogenation. The NiNP in NiNP2@NiSA2-NG promoted the formation of H* and reduced the energy barrier of *CO2 hydrogenation to *COOH, and CO desorption can be efficiently facilitated by NiSA sites, thereby resulting in enhanced CO2RR performance. 相似文献
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Tianyang Chen Jinghu Ji Yonghong Fu Xiping Yang Hao Fu Lunan Fang 《Ceramics International》2021,47(16):23162-23180
The performance of mechanical seals can be improved by using multi-scale composite textures with spiral grooves and micro-dimples, but without a clear texture function mechanism, it is difficult to optimize the textures on the sealing surface. This research established a mathematical model based on the mass-conservative JFO cavitation boundary to analyze the mechanical seal performance of multi-scale composite micro-textures. We use the multi-grid method for numerical solutions, investigate the hydrodynamic lubrication characteristics of composite-textured mechanical seals, and inspect the coupling effect of micro-dimples and spiral grooves. We also analyzed the influence of the geometrical parameters of composite textures on the sealing performance and optimized the sealing surface textures using theoretical analysis. The numerical analysis showed that the multi-scale composite-textured mechanical seal produced a coupling effect between the micro-dimples and spiral grooves, which improved the lubrication of the sealing pair. Eventually, C/SiC mechanical seal bench tests confirmed the tribological improvement of composite textures compared with the un-textured seal under various sealing liquid pressures and rotation speeds. Through comparing the Stribeck curve, the multi-scale composite textured C/SiC mechanical seals have a lower and more stable friction torque than the un-textured. 相似文献
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