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GAN与Diffusion在传统纹样设计中的实验研究
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作者 李莉 毛子晗 +2 位作者 吕思奇 袁晨旭 彭玉旭 《丝绸》 CAS CSCD 北大核心 2024年第8期9-22,共14页
传统纹样是中国优秀传统文化的重要组成部分,传统人工设计已经无法满足纹样的现代设计需求,生成式AI为传统纹样设计提供了新的设计路径和方法。文章将生成式AI应用于传统纹样设计中,通过适配实验优选基于GAN的Style GAN和基于Diffusion... 传统纹样是中国优秀传统文化的重要组成部分,传统人工设计已经无法满足纹样的现代设计需求,生成式AI为传统纹样设计提供了新的设计路径和方法。文章将生成式AI应用于传统纹样设计中,通过适配实验优选基于GAN的Style GAN和基于Diffusion的Stable Diffusion两种主流图像生成模型进行实验,采用技术分析与艺术分析相结合,对实验结果进行多角度、多维度对比分析,为设计师选择生成设计方法提供参照。实验结果表明,两个模型均能满足基本的艺术设计需求。Style GAN模型生成的纹样图像更接近真实图像的分布,具有更高的图像质量和多样性;Stable Diffusion模型能较好地传承传统纹样的基因,艺术性与创造性兼具,更加符合传统纹样的艺术设计需求。 展开更多
关键词 GAN DIFFUSION 传统纹样 评价指标 对比分析 实验研究
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ControlNet插件在AI生成图像中的控制应用分析 被引量:1
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作者 温逸娴 《影视制作》 2024年第2期57-62,共6页
运用AI绘图工具Stable Diffusion生成图像的过程中,虽然可以用提示词来描述画面,但生成图像的不确定性很大。为了生成满意的图像,可以使用Stable Diffusion的插件ControlNet对图像生成进行控制。本文分析了用ControlNet对图像生成过程... 运用AI绘图工具Stable Diffusion生成图像的过程中,虽然可以用提示词来描述画面,但生成图像的不确定性很大。为了生成满意的图像,可以使用Stable Diffusion的插件ControlNet对图像生成进行控制。本文分析了用ControlNet对图像生成过程的控制方法,并运用该方法在具体案例中实现了在生成图像过程中对画面构图的控制。 展开更多
关键词 AIGC AI绘画 Stable Diffusion CONTROLNET 人工智能
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AIGC视野下的浙北民居风格研究路径初探 被引量:1
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作者 陆激 沈东山 《建筑与文化》 2024年第2期2-9,共8页
文章以Stable Diffusion为工具,以通过机器学习特定建筑风格图像并输出结果的方式,尝试对浙北民居的建筑风格在AIGC视野下的研究路径进行探索。文章建立了浙北民居与现代住宅图像的数据集并进行训练,得到该语境下的浙北民居风格模型,接... 文章以Stable Diffusion为工具,以通过机器学习特定建筑风格图像并输出结果的方式,尝试对浙北民居的建筑风格在AIGC视野下的研究路径进行探索。文章建立了浙北民居与现代住宅图像的数据集并进行训练,得到该语境下的浙北民居风格模型,接着通过批量单独生成与混合生成,对生成的结果进行分类统计。最终发现了该模型在建筑风格模拟方面具有不同于人类直觉判断的抽象提取能力,进而概括了该类工具下生成结果的可能性与局限性。 展开更多
关键词 AIGC Stable Diffusion 机器学习 浙北民居 建筑风格
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从特征辨识到图像生成:基于AIGC范式的苗族服饰设计 被引量:7
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作者 于鹏 张毅 《丝绸》 CAS CSCD 北大核心 2024年第3期1-10,共10页
苗族服饰是中国民族服饰体系中重要的组成部分,在商品化发展中开辟了广阔的市场,但产品同质化现象将阻碍民族文化的进一步发展,人工智能生成内容(AIGC)的发展为传统服饰设计提供了新的可能。文章基于苗族服饰现代化的需要,通过搭建多模... 苗族服饰是中国民族服饰体系中重要的组成部分,在商品化发展中开辟了广阔的市场,但产品同质化现象将阻碍民族文化的进一步发展,人工智能生成内容(AIGC)的发展为传统服饰设计提供了新的可能。文章基于苗族服饰现代化的需要,通过搭建多模型组合流程,为苗族服饰成衣化设计提供灵感样本。实验结果表明,以服饰辨识性为基础,采用Lora训练方式,仅需少量样本即可实现苗族服饰特征在Stable Diffusion生成内容中的迁移。将深度学习引入非遗服饰现代化的进程中,旨在助力非遗服饰朝着成衣化、多样化、大众化方向发展,以数字化方式推动民族服饰转型升级。 展开更多
关键词 AIGC 苗族 非遗服饰 少样本风格迁移 Stable Diffusion Lora 辅助设计
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基于美学梯度法的人工智能风格化绘画系统 被引量:1
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作者 钟梓锐 梁玲琳 《浙江理工大学学报(自然科学版)》 2024年第4期537-547,共11页
当前Stable diffusion等人工智能绘画模型在绘画时难以直接控制图像风格,同时风格模型训练仅针对单种风格。针对该问题,提出了一种基于美学梯度法的人工智能风格化绘画系统,以实现多种图像风格的控制和融合,并提供更加便捷的图像创作体... 当前Stable diffusion等人工智能绘画模型在绘画时难以直接控制图像风格,同时风格模型训练仅针对单种风格。针对该问题,提出了一种基于美学梯度法的人工智能风格化绘画系统,以实现多种图像风格的控制和融合,并提供更加便捷的图像创作体验。收集并分析网络用户数据,结合问卷得到用户对图像风格的感性需求;根据感性需求收集各风格图像数据得到对应的风格图像训练集。使用梯度下降算法计算风格化文本编码器的权重,实现生成图像风格化的效果。通过可用性测试对比用户对该系统与传统人工智能绘画系统产出图像的风格满意程度,结果表明:人工智能风格化绘画系统的平均满意度相较传统人工智能绘画系统提升23%,表明人工智能风格化绘画系统在图像风格生成上具有更好的效果,可满足用户对图像风格的需求。该人工智能风格化绘画系统可以更便捷地实现图像风格调整,允许用户直观选择不同风格的权重,便捷使用一种或多种风格,能够有效满足用户对图像风格设计的需求。 展开更多
关键词 人工智能绘画模型 Stable diffusion 美学梯度法 感性需求 风格化
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基于Stable Diffusion的虚拟人形象预设计的应用与研究 被引量:2
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作者 曾建勇 沈晓萍 《现代信息科技》 2024年第3期169-175,共7页
对当前AIGC在虚拟形象预设计方面的现状及影响进行了分析和探讨。以Stable Diffusion为例,详细介绍了工程构建和实现,对相关模块的作用、运行环境、使用方法及其指令等多个方面进行了综合叙述、分析和探讨,针对使用不同采样方法、不同... 对当前AIGC在虚拟形象预设计方面的现状及影响进行了分析和探讨。以Stable Diffusion为例,详细介绍了工程构建和实现,对相关模块的作用、运行环境、使用方法及其指令等多个方面进行了综合叙述、分析和探讨,针对使用不同采样方法、不同采样参数及不同训练模型生成图片效果的优劣进行了说明及展示。随后,通过项目实例,完整地展示了人物形象预设计的过程。最后,对AIGC等新技术可能带来的社会影响进行了预测和总结。 展开更多
关键词 AI生成内容 Stable Diffusion 生成对抗网络 提示词 虚拟人形象
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Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19 被引量:1
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作者 Zhiding ZHANG Xu YUE +3 位作者 Hao ZHOU Jun ZHU Yadong LEI Chenguang TIAN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第1期84-96,共13页
The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).Whil... The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming. 展开更多
关键词 diffuse radiation fertilization effects anthropogenic aerosols natural aerosols pan-Arctic net primary productivity
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Microstructure and thermal properties of dissimilar M300–CuCr1Zr alloys by multi-material laser-based powder bed fusion 被引量:1
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作者 Xiaoshuang Li Dmitry Sukhomlinov Zaiqing Que 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期118-128,共11页
Multi-material laser-based powder bed fusion (PBF-LB) allows manufacturing of parts with 3-dimensional gradient and additional functionality in a single step. This research focuses on the combination of thermally-cond... Multi-material laser-based powder bed fusion (PBF-LB) allows manufacturing of parts with 3-dimensional gradient and additional functionality in a single step. This research focuses on the combination of thermally-conductive CuCr1Zr with hard M300 tool steel.Two interface configurations of M300 on CuCr1Zr and CuCr1Zr on M300 were investigated. Ultra-fine grains form at the interface due to the low mutual solubility of Cu and steel. The material mixing zone size is dependent on the configurations and tunable in the range of0.1–0.3 mm by introducing a separate set of parameters for the interface layers. Microcracks and pores mainly occur in the transition zone.Regardless of these defects, the thermal diffusivity of bimetallic parts with 50vol% of CuCr1Zr significantly increases by 70%–150%compared to pure M300. The thermal diffusivity of CuCr1Zr and the hardness of M300 steel can be enhanced simultaneously by applying the aging heat treatment. 展开更多
关键词 multi-material additive manufacturing laser-based powder bed fusion thermal diffusivity dissimilar metals copper alloy
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Construction of Dynamic Alloy Interfaces for Uniform Li Deposition in Li-Metal Batteries 被引量:1
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作者 Qingwen Li Yulu Liu +7 位作者 Ziheng Zhang Jinjie Chen Zelong Yang Qibo Deng Alexander V.Mumyatov Pavel A.Troshin Guang He Ning Hu 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第3期64-71,共8页
It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely ... It is well accepted that a lithiophilic interface can effectively regulate Li deposition behaviors,but the influence of the lithiophilic interface is gradually diminished upon continuous Li deposition that completely isolates Li from the lithiophilic metals.Herein,we perform in-depth studies on the creation of dynamic alloy interfaces upon Li deposition,arising from the exceptionally high diffusion coefficient of Hg in the amalgam solid solution.As a comparison,other metals such as Au,Ag,and Zn have typical diffusion coefficients of 10-20 orders of magnitude lower than that of Hg in the similar solid solution phases.This difference induces compact Li deposition pattern with an amalgam substrate even with a high areal capacity of 55 mAh cm^(-2).This finding provides new insight into the rational design of Li anode substrate for the stable cycling of Li metal batteries. 展开更多
关键词 diffusion coefficient dynamic alloy interfaces Li dendrites Li solid solution uniform Li deposition
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Value of multiple models of diffusion-weighted imaging to predict hepatic lymph node metastases in colorectal liver metastases patients 被引量:1
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作者 Hai-Bin Zhu Bo Zhao +3 位作者 Xiao-Ting Li Xiao-Yan Zhang Qian Yao Ying-Shi Sun 《World Journal of Gastroenterology》 SCIE CAS 2024年第4期308-317,共10页
BACKGROUND About 10%-31% of colorectal liver metastases(CRLM)patients would concomitantly show hepatic lymph node metastases(LNM),which was considered as sign of poor biological behavior and a relative contraindicatio... BACKGROUND About 10%-31% of colorectal liver metastases(CRLM)patients would concomitantly show hepatic lymph node metastases(LNM),which was considered as sign of poor biological behavior and a relative contraindication for liver resection.Up to now,there’s still lack of reliable preoperative methods to assess the status of hepatic lymph nodes in patients with CRLM,except for pathology examination of lymph node after resection.AIM To compare the ability of mono-exponential,bi-exponential,and stretchedexponential diffusion-weighted imaging(DWI)models in distinguishing between benign and malignant hepatic lymph nodes in patients with CRLM who received neoadjuvant chemotherapy prior to surgery.METHODS In this retrospective study,97 CRLM patients with pathologically confirmed hepatic lymph node status underwent magnetic resonance imaging,including DWI with ten b values before and after chemotherapy.Various parameters,such as the apparent diffusion coefficient from the mono-exponential model,and the true diffusion coefficient,the pseudo-diffusion coefficient,and the perfusion fraction derived from the intravoxel incoherent motion model,along with distributed diffusion coefficient(DDC)andαfrom the stretched-exponential model(SEM),were measured.The parameters before and after chemotherapy were compared between positive and negative hepatic lymph node groups.A nomogram was constructed to predict the hepatic lymph node status.The reliability and agreement of the measurements were assessed using the coefficient of variation and intraclass correlation coefficient.RESULTS Multivariate analysis revealed that the pre-treatment DDC value and the short diameter of the largest lymph node after treatment were independent predictors of metastatic hepatic lymph nodes.A nomogram combining these two factors demonstrated excellent performance in distinguishing between benign and malignant lymph nodes in CRLM patients,with an area under the curve of 0.873.Furthermore,parameters from SEM showed substantial repeatability.CONCLUSION The developed nomogram,incorporating the pre-treatment DDC and the short axis of the largest lymph node,can be used to predict the presence of hepatic LNM in CRLM patients undergoing chemotherapy before surgery.This nomogram was proven to be more valuable,exhibiting superior diagnostic performance compared to quantitative parameters derived from multiple b values of DWI.The nomogram can serve as a preoperative assessment tool for determining the status of hepatic lymph nodes and aiding in the decision-making process for surgical treatment in CRLM patients. 展开更多
关键词 Colorectal cancer Individualized treatment Diffusion magnetic resonance imaging Intravoxel incoherent motion LIVER
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Effect of Cosmic Plasma on the Observation of Supernovae Ia 被引量:1
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作者 Yi-Jia Zheng 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第2期46-49,共4页
In observational cosmology,a supernova la is used as a standard candle in order to extend the Hubble diagram to a higher redshift range.Astrophysicists found that the observed brightness of high redshift supernovae la... In observational cosmology,a supernova la is used as a standard candle in order to extend the Hubble diagram to a higher redshift range.Astrophysicists found that the observed brightness of high redshift supernovae la is dimmer than expected.This dimming effect is considered observational evidence for the existence of dark energy in the universe.It should be noted that this conclusion is based on an assumption that the mass density of the cosmic plasma is very small.Therefore,the dimming effect caused by the Compton scattering of free electrons in cosmic plasma can be neglected.X-ray observations suggest that the mass density of the cosmic plasma may be very large.In theory,the observed dimming effect of high redshift supernovae Ia may be caused by the Compton scattering of free electrons in the cosmic plasma.In this paper it will be shown that this idea is reasonable.Therefore,there is no need to introduce the confusing concept of dark energy into cosmology. 展开更多
关键词 Cosmology-cosmology observations-cosmology theory-(cosmology:)dark energy-(cosmology:)listance scale-X-rays diffuse background-plasmas-opacity
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Glymphatic function and its influencing factors in different glucose metabolism states 被引量:1
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作者 Bin Tian Chen Zhao +7 位作者 Jia-Li Liang Hui-Ting Zhang Yi-Fan Xu Hui-Lei Zheng Jia Zhou Jiang-Nian Gong Shu-Ting Lu Zi-San Zeng 《World Journal of Diabetes》 SCIE 2024年第7期1537-1550,共14页
BACKGROUND Dysfunction of the glymphatic system in the brain in different stages of altered glucose metabolism and its influencing factors are not well characterized.AIM To investigate the function of the glymphatic s... BACKGROUND Dysfunction of the glymphatic system in the brain in different stages of altered glucose metabolism and its influencing factors are not well characterized.AIM To investigate the function of the glymphatic system and its clinical correlates in patients with different glucose metabolism states,the present study employed diffusion tensor imaging along the perivascular space(DTI-ALPS)index.METHODS Sample size was calculated using the pwr package in R software.This crosssectional study enrolled 22 patients with normal glucose metabolism(NGM),20 patients with prediabetes,and 22 patients with type 2 diabetes mellitus(T2DM).A 3.0T magnetic resonance imaging was used to evaluate the function of the glymphatic system.The mini-mental state examination(MMSE)was used to assess general cognitive function.The DTI-ALPS index of bilateral basal ganglia and the mean DTI-ALPS index was calculated.Further,the correlation between DTI-ALPS and clinical features was assessed.RESULTS The left-side,right-side,and mean DTI-ALPS index in the T2DM group were significantly lower than that in the NGM group.The right-side DTI-ALPS and mean DTI-ALPS index in the T2DM group were significantly lower than those in the prediabetes group.DTI-ALPS index lateralization was not observed.The MMSE score in the T2DM group was significantly lower than that in the NGM and prediabetes group.After controlling for sex,the left-side DTI-ALPS and mean DTI-ALPS index in the prediabetes group were positively correlated with 2-hour postprandial blood glucose level;the left-side DTI-ALPS index was negatively correlated with total cholesterol and low-density lipoprotein level.The right-side DTI-ALPS and mean DTI-ALPS index were negatively correlated with the glycosylated hemoglobin level and waist-to-hip ratio in the prediabetes group.The left-side,right-side,and mean DTI-ALPS index in the T2DM group were positively correlated with height.The left-side and mean DTIALPS index in the T2DM group were negatively correlated with high-density lipoprotein levels.CONCLUSION Cerebral glymphatic system dysfunction may mainly occur in the T2DM stage.Various clinical variables were found to affect the DTI-ALPS index in different glucose metabolism states.This study enhances our understanding of the pathophysiology of diabetic brain damage and provides some potential biological evidence for its early diagnosis. 展开更多
关键词 Glymphatic system PREDIABETES Type 2 diabetes mellitus Magnetic resonance imaging Diffusion tensor imaging along the perivascular space
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基于提示词优化的AIGC汉长安城遗址儿童绘本应用研究
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作者 王妍 官巍 李忠绵 《丝网印刷》 2024年第17期98-100,共3页
以汉长安城遗址中椒房殿为测试对象,探究和优化Stable Diffusion中的提示词输入策略生成椒房殿复原设想图,并且依据该输入逻辑制作出儿童绘本素材图。研究将AI绘画、汉文化和儿童绘本创新性的融合,对于AI艺术应用和儿童美育教育实践具... 以汉长安城遗址中椒房殿为测试对象,探究和优化Stable Diffusion中的提示词输入策略生成椒房殿复原设想图,并且依据该输入逻辑制作出儿童绘本素材图。研究将AI绘画、汉文化和儿童绘本创新性的融合,对于AI艺术应用和儿童美育教育实践具有可供参考的推广价值。 展开更多
关键词 Stable Diffusion 儿童绘本 提示词 汉长安城遗址
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基于生成式AI的人工智能在建筑设计中的应用探究 被引量:1
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作者 邓元媛 杨楠 王子晴 《智能建筑与智慧城市》 2024年第7期9-12,共4页
近两年间人工智能(AI)相关技术逐步由顶端智能产业下放,走进越来越多诸如建筑等传统行业中。把握住与新型技术相结合的机会是建筑设计领域一种可探索的道路。文章将以生成式AI为例,从应用领域、应用模式、方案生成等视角,探究人工智能... 近两年间人工智能(AI)相关技术逐步由顶端智能产业下放,走进越来越多诸如建筑等传统行业中。把握住与新型技术相结合的机会是建筑设计领域一种可探索的道路。文章将以生成式AI为例,从应用领域、应用模式、方案生成等视角,探究人工智能在建筑方案设计领域可以为建筑师提供的参考和帮助,并提出其中的缺陷与局限性,为今后人工智能在建筑设计领域更加深入、系统地应用提供参考。 展开更多
关键词 人工智能 生成式AI AI建筑设计 Stable Diffusion
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Diffuseness effect and radial basis function network for optimizing α decay calculations 被引量:2
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作者 Na-Na Ma Xiao-Jun Bao Hong-Fei Zhang 《Chinese Physics C》 SCIE CAS CSCD 2021年第2期459-466,共8页
A radial basis function network(RBFN)approach is adopted for the first time to optimize the calculation of$\alpha$decay half-life in the generalized liquid drop model(GLDM),while concurrently incorporating the surface... A radial basis function network(RBFN)approach is adopted for the first time to optimize the calculation of$\alpha$decay half-life in the generalized liquid drop model(GLDM),while concurrently incorporating the surface diffuseness effect.The calculations presented herein agree closely with the experimental half-lives for 68 superheavy nuclei(SHN),achieving a remarkable reduction of 40%in the root-mean-square(rms)deviations of half-lives.Furthermore,using the RBFN method,the half-lives for four SHN isotopes,252-288Rf,272-310Fl,286-316119,and 292-318120,are predicted using the improved GLDM with the diffuseness correction and the decay energies from WS4 and FRDM as inputs.Therefore,we conclude that the diffuseness effect should be embodied in the proximity energy.Moreover,increased application of neural network methods in nuclear reaction studies is encouraged. 展开更多
关键词 αdecay radial basis function network the surface diffuseness effect
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Spatial sensitivity to absorption changes for various near-infrared spectroscopy methods:A compendium review
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作者 Giles Blaney Angelo Sassaroli Sergio Fantini 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第4期1-115,共115页
This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three tempo... This compendium review focuses on the spatial distribution of sensitivity to localized absorption changes in optically diffuse media,particularly for measurements relevant to near-infrared spectroscopy.The three temporal domains,continuous wave,frequency domain,and time domain,each obtain different optical data types whose changes may be related to effective homogeneous changes in the absorption coefficient.Sensitivity is the relationship between a localized perturbation and the recovered effective homogeneous absorption change.Therefore,spatial sensitivity maps representing the perturbation location can be generated for the numerous optical data types in the three temporal domains.The review first presents a history of the past 30 years of work investigating this sensitivity in optically diffuse media.These works are experimental and theoretical,presenting one-,two-,and three-dimensional sensitivity maps for different Near-Infrared Spectroscopy methods,domains,and data types.Following this history,we present a compendium of sensitivity maps organized by temporal domain and then data type.This compendium provides a valuable tool to compare the spatial sensitivity of various measurement methods and parameters in one document.Methods for one to generate these maps are provided in Appendix A,including the code.This historical review and comprehensive sensitivity map compendium provides a single source researchers may use to visualize,investigate,compare,and generate sensitivity to localized absorption change maps. 展开更多
关键词 Diffuse optics diffusion theory Monte Carlo spatial sensitivity absorption perturbations near-infrared spectroscopy CONTINUOUS-WAVE FREQUENCY-DOMAIN time-domain
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Similarities and differences in inherent mechanism and characteristic frequency between the one-dimensional poroelastic model and the layered White model
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作者 Li-Ming Zhao Cai-Ping Lu +1 位作者 Yang Liu Chao-Chao Li 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2383-2392,共10页
The similarities and differences in inherent mechanism and characteristic frequency between the onedimensional(1D)poroelastic model and the layered White model were investigated.This investigation was conducted under ... The similarities and differences in inherent mechanism and characteristic frequency between the onedimensional(1D)poroelastic model and the layered White model were investigated.This investigation was conducted under the assumption that the rock was homogenous and isotropic at the mesoscopic scale.For the inherent mechanism,both models resulted from quasi-static flow in a slow P-wave diffusion mode,and the differences between them originated from saturated fluids and boundary conditions.On the other hand,for the characteristic frequencies of the models,the characteristic frequency of the 1D poroelastic model was first modified because the elastic constant and formula for calculating it were misused and then compared to that of the layered White model.Both of them moved towards higher frequencies with increasing permeability and decreasing viscosity and diffusion length.The differences between them were due to the diffusion length.The diffusion length for the 1D poroelastic model was determined by the sample length,whereas that for the layered White model was determined by the length of the representative elementary volume(REV).Subsequently,a numerical example was presented to demonstrate the similarities and differences between the models.Finally,published experimental data were interpreted using the 1D poroelastic model combined with the Cole-Cole model.The prediction of the combined model was in good agreement with the experimental data,thereby validating the effectiveness of the 1D poroelastic model.Furthermore,the modified characteristic frequency in our study was much closer to the experimental data than the previous prediction,validating the effectiveness of our modification of the characteristic frequency of the 1D poroelastic model.The investigation provided insight into the internal relationship between wave-induced fluid flow(WIFF)models at macroscopic and mesoscopic scales and can aid in a better understanding of the elastic modulus dispersion and attenuation caused by the WIFF at different scales. 展开更多
关键词 1D poroelastic model Layered White model Quasi-static flow Slow P-wave diffusion Characteristic frequency Diffusion length
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从Make-A-Video到Sora:AI视频生成技术的进步与挑战
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作者 郑凯 王菂 袁堂青 《科技视界》 2024年第4期74-77,共4页
随着人工智能技术的飞速发展,AI视频生成技术已成为研究和应用的热点。从Meta的MakeA-Video, Runway AI的Runway Gen-2,Stability AI的Stable Video Diffusion,到Google的Lumiere,再到OpenAI的Sora,每一个模型的推出都不仅代表了AI视频... 随着人工智能技术的飞速发展,AI视频生成技术已成为研究和应用的热点。从Meta的MakeA-Video, Runway AI的Runway Gen-2,Stability AI的Stable Video Diffusion,到Google的Lumiere,再到OpenAI的Sora,每一个模型的推出都不仅代表了AI视频生成技术的进步,也带来了新的挑战。回顾了这些关键AI视频模型的原理和特点,并对比它们之间的优势和不足,探讨了AI视频生成技术面临的主要挑战,展望了未来的发展方向。 展开更多
关键词 AI视频生成 Make-A-Video Runway Gen-2 Stable Video Diffusion Lumiere SORA 封闭模型 开源模型
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Research on the correlation between the dual diffusion behavior of zinc in InGaAs/InP single-photon avalanche photodiodes and device performance
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作者 LIU Mao-Fan YU Chun-Lei +7 位作者 MA Ying-Jie YU Yi-Zhen YANG Bo TIAN Yu BAO Peng-Fei CAO Jia-Sheng LIU Yi LI Xue 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2024年第5期595-602,共8页
The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribu... The development of InGaAs/InP single-photon avalanche photodiodes(SPADs)necessitates the utiliza-tion of a two-element diffusion technique to achieve accurate manipulation of the multiplication width and the dis-tribution of its electric field.Regarding the issue of accurately predicting the depth of diffusion in InGaAs/InP SPAD,simulation analysis and device development were carried out,focusing on the dual diffusion behavior of zinc atoms.A formula of X_(j)=k√t-t_(0)+c to quantitatively predict the diffusion depth is obtained by fitting the simulated twice-diffusion depths based on a two-dimensional(2D)model.The 2D impurity morphologies and the one-dimensional impurity profiles for the dual-diffused region are characterized by using scanning electron micros-copy and secondary ion mass spectrometry as a function of the diffusion depth,respectively.InGaAs/InP SPAD devices with different dual-diffusion conditions are also fabricated,which show breakdown behaviors well consis-tent with the simulated results under the same junction geometries.The dark count rate(DCR)of the device de-creased as the multiplication width increased,as indicated by the results.DCRs of 2×10^(6),1×10^(5),4×10^(4),and 2×10^(4) were achieved at temperatures of 300 K,273 K,263 K,and 253 K,respectively,with a bias voltage of 3 V,when the multiplication width was 1.5µm.These results demonstrate an effective prediction route for accu-rately controlling the dual-diffused zinc junction geometry in InP-based planar device processing. 展开更多
关键词 InGaAs/InP single-photon avalanche photodiode diffusion depth Znic diffusion dark count rate
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Thiourea crystal growth kinetics,mechanism and process optimization during cooling crystallization
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作者 Zhongxiang Ding Wei Song +2 位作者 Tong Zhou Weihua Cui Changsong Wang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第9期62-69,共8页
In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine crystals.This investigation delves into the growth kinetics and me... In the cooling crystallization process of thiourea,a significant issue is the excessively wide crystal size distribution(CSD)and the abundance of fine crystals.This investigation delves into the growth kinetics and mechanisms governing thiourea crystals during the cooling crystallization process.The fitting results indicate that the crystal growth rate coefficient,falls within the range of 10^(-7)to 10^(-8)m·s^(-1).Moreover,with decreasing crystallization temperature,the growth process undergoes a transition from diffusion-controlled to surface reaction-controlled,with temperature primarily influencing the surface reaction process and having a limited impact on the diffusion process.Comparing the crystal growth rate,and the diffusion-limited growth rate,at different temperatures,it is observed that the crystal growth process can be broadly divided into two stages.At temperatures above 25℃,1/qd(qd is diffusion control index)approaches 1,indicating the predominance of diffusion control.Conversely,at temperatures below 25℃,1/qd increases rapidly,signifying the dominance of surface reaction control.To address these findings,process optimization was conducted.During the high-temperature phase(35-25℃),agitation was increased to reduce the limitations posed by bulk-phase diffusion in the crystallization process.In the low-temperature phase(25-15℃),agitation was reduced to minimize crystal breakage.The optimized process resulted in a thiourea crystal product with a particle size distribution predominantly ranging from 0.7 to 0.9 mm,accounting for 84%of the total.This study provides valuable insights into resolving the issue of excessive fine crystals in the thiourea crystallization process. 展开更多
关键词 THIOUREA CRYSTALLIZATION Growth kinetics Process optimization DIFFUSION Surface reaction
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