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Transfer-free CVD graphene for highly sensitive glucose sensors 被引量:1
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作者 Shijing Wei Yabin Hao +7 位作者 Zhe Ying Chuan Xu Qinwei Wei Sen Xue Hui-Ming Cheng Wencai Ren Lai-Peng Ma You Zeng 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第2期71-76,共6页
Chemical vapor deposition(CVD)graphene film is a promising electrode-modifying material for fabricating high-performance glucose sensor due to its high electrical conductivity and two-dimensional structure over large ... Chemical vapor deposition(CVD)graphene film is a promising electrode-modifying material for fabricating high-performance glucose sensor due to its high electrical conductivity and two-dimensional structure over large area.However,the use of typical metal-based CVD graphene suffers from the residue contamination of polymer transfer-support and heavy metal ions.In this work,we directly grew fewlayer graphene on the SiO2/Si substrate without transfer process and then fabricated graphene-based glucose sensors by sequentially immobilizing glucose oxidase and depositing Nafion layer on its surface that was functionalized by oxygen-plasma treatment.Our transfer-and metal-free process shows distinct advantage over the common metal-CVD method in improving the electrochemical performance by eliminating the contamination of transfer-residue.Thus-obtained glucose sensor shows a high sensitivity(16.16μA mM-1cm-2)with a detection limit of 124.19μM.This method is simple and promising for the development of highly sensitive glucose sensors. 展开更多
关键词 GRAPHENE Chemical vapor DEPOSITION transfer-free Oxygen-plasma treatment GLUCOSE sensor
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Farmers' Land Transfer-out Behavior from the Perspective of Household Livelihood Endowment Based on the Survey in Anhui,Hubei and Sichuan 被引量:2
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作者 Zhangjin FEI 《Asian Agricultural Research》 2018年第6期23-29,共7页
Based on the household livelihood endowment theory and the survey of 367 farmer households in Anhui,Hubei,and Sichuan in 2016,and using the orderly multi-category logistic model,the behavioral decision of farmers in t... Based on the household livelihood endowment theory and the survey of 367 farmer households in Anhui,Hubei,and Sichuan in 2016,and using the orderly multi-category logistic model,the behavioral decision of farmers in the land circulation was discussed to explore the key parameters influencing the land transfer-out. It found that decisions of farmers on land transfer-out behavior are affected by many factors.Specifically,household non-agricultural income and per capita land area significantly reduce farmers' willingness to transfer land,while the household head age,agricultural input-output ratio,and confirmation of land right significantly promote the farmers' decision on land transferout. Therefore,increasing the allocation efficiency of household livelihood endowment has important policy value and practical significance for eliminating unreasonable land circulation and promoting large-scale agricultural production. 展开更多
关键词 Household livelihood endowment Land transfer-out Orderly multi-category logistic model
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On U(1) Gauge Theory Transfer-Matrix in Fourier Basis
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作者 Narges Vadood Amir H.Fatollahi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2019年第8期921-926,共6页
The properties of the transfer-matrix of U(1) lattice gauge theory in the Fourier basis are explored.Among other statements it is shown:(i) the transfer-matrix is block-diagonal,(ii) all consisting vectors of a block ... The properties of the transfer-matrix of U(1) lattice gauge theory in the Fourier basis are explored.Among other statements it is shown:(i) the transfer-matrix is block-diagonal,(ii) all consisting vectors of a block are known based on an arbitrary block vector,(iii) the ground-state belongs to the zero-mode’s block.The emergence of maximum-points in matrix-elements as functions of the gauge coupling is clarified.Based on explicit expressions for the matrix-elements we present numerical results as tests of our statements. 展开更多
关键词 LATTICE GAUGE theories transfer-MATRIX method energy SPECTRUM
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Study of a mass transfer-reaction model for SO_2 absorption process using LAS/H_2SO_4 solution
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作者 Yue Changtao Li Shuyuan +3 位作者 Chen Weihong Guo Shaohui Yang Yuhua Sha Yingxun 《Petroleum Science》 SCIE CAS CSCD 2010年第3期397-402,共6页
A regenerative absorption process for removal of SOx from FCC off-gas using LAS/ H2SO4 solution as absorbant was studied and pilot-plant experiments were carried out. A mass transfer- reaction model for the SO2 absorp... A regenerative absorption process for removal of SOx from FCC off-gas using LAS/ H2SO4 solution as absorbant was studied and pilot-plant experiments were carried out. A mass transfer- reaction model for the SO2 absorption process was established based on pilot-plant experiments, and the concentration distribution of components in the liquid film, and the partial pressure and mass transfer rate of SO2 along the height of the absorption tower, was calculated from this model. The numerical simulation results were compared with the experimental results and proved that the model can be used for describing the SO2 absorption process. 展开更多
关键词 Regenerative absorption process SOx cleanup LAS/H2SO4 solution mass transfer-reactionmodel
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Cu(0) Wire-mediated Single-electron Transfer-living Radical Polymerization of Oligo(ethylene oxide) Methyl Ether Acrylate by Selecting the Optimal Reaction Conditions
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作者 Liang Ding Juan Li +3 位作者 Rui-Yu Jiang Ling-Fang Wang Wei Song Lei Zhu 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2019年第11期1130-1141,共12页
The efficient Cu(0) wire-catalyzed single-electron transfer-living radical polymerization (SET-LRP) in organic solvents and mixtures of the organic solvents with water has been thoroughly investigated. 01igo(ethylene ... The efficient Cu(0) wire-catalyzed single-electron transfer-living radical polymerization (SET-LRP) in organic solvents and mixtures of the organic solvents with water has been thoroughly investigated. 01igo(ethylene oxide) methyl ether acrylate was used as an exemplar oligomer monomer to determine the optimum polymerization conditions for rapid, controlled, and quantitative production of well-defined polymers. The effects of Cu(0)-wire length (12.5 or 4.5 cm), ligand type (tris(dimethylaminoethyl)amine, Me6-TREN, or tris(2-aminoethyl)amine, TREN), and solvent type (dipolar aprotic solvents, cyclic ethers, alcohol, or acetone) on the polymerization have been evaluated. Kinetic experiments were performed for all polymerizations to assess the "living" behavior of each system employed. Importantly, TREN could be used as a replacement for Me6-TREN in Cu(0) wire-catalyzed SET-LRP of oligomer monomer, which probably provides the most economical and efficient methodology since TREN is 80 times less expensive than Me6-TREN. The high chain-end fidelity of resulting polymer was experimentally verified by thiol-Michael addition reaction at the a-Br chain end and subsequent chain extension with methyl acrylate. 展开更多
关键词 SINGLE-ELECTRON transfer-living RADICAL POLYMERIZATION Oligo(ethylene oxide) methyl ETHER ACRYLATE Kinetics of POLYMERIZATION Modification
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A Simple but Accurate Ultraviolet Limb-Scan Spherically-Layered Radiative-Transfer-Model Based on Single-Scattering Physics 被引量:3
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作者 郭霞 吕达仁 吕曜 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2007年第4期619-630,共12页
Here we present a study focusing on atmospheric limb-scattered radiative characteristics in the ultraviolet band by using a limb-scan spherically-layered radiative-transfer-model based on the single-scattering approxi... Here we present a study focusing on atmospheric limb-scattered radiative characteristics in the ultraviolet band by using a limb-scan spherically-layered radiative-transfer-model based on the single-scattering approximation, which was developed by the present authors. We have applied an accurate numerical integration technique involving an auto-adaptive modified-space step, which assured high accuracy and simplification. Comparisons were made to the newly released spherical radiative transfer model, SCIATRAN2.0, which was developed by Institute of Remote Sensing/Institute of Environmental Physics (IUP/IFE) at University of Bremen and to measurements collected via an ultraviolet spectrometer on the Solar Mesospheric Explorer (SME) satellite, which was launched in October, 1981. Preliminary results indicate that the present model provides a good interpretation of the earth-limb scattered ultraviolet radiance, and thus, is suitable for the study of the ultraviolet-limb radiative-transfer problem with high accuracy. 展开更多
关键词 ULTRAVIOLET limb geometry spherical atmosphere radiative-transfer model
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基于Transfer-SVM多标签文本分类算法研究 被引量:2
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作者 李程文 宋文广 谭建平 《无线互联科技》 2019年第10期102-103,共2页
传统的支持向量机分类模型只有在利用大量已标注数据进行训练才能获得较高精度。在实际应用中,多标签数据相对于传统单标签数据更具有价值,但多标签数据中含有大量冗余数据,获取大量多标签数据难度非常大。文章提出一种基于迁移学习的... 传统的支持向量机分类模型只有在利用大量已标注数据进行训练才能获得较高精度。在实际应用中,多标签数据相对于传统单标签数据更具有价值,但多标签数据中含有大量冗余数据,获取大量多标签数据难度非常大。文章提出一种基于迁移学习的分类算法,利用目标数据域和源数据域的相关性,从源数据域中选取对分类超平面起关键作用的支持向量和目标数据域,一起训练分类模型以提高分类精度。 展开更多
关键词 多标签 迁移学习 文本分类 支持向量机
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Optimization of the Classic Transfer-Stacking Model Migration Algorithm: A Way to Solve Time-Varying Performance Degradation of Acute Kidney Injury Clinical Prediction Model
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作者 Yunfei Xue 《Journal of Biosciences and Medicines》 2021年第4期14-28,共15页
Acute Kidney Injury (AKI) is one of the most common acute and critical illnesses in general wards and intensive care units. Its high morbidity and high fatality rate have become a major global public health problem. T... Acute Kidney Injury (AKI) is one of the most common acute and critical illnesses in general wards and intensive care units. Its high morbidity and high fatality rate have become a major global public health problem. There are often serious lags in clinical diagnosis of AKI. Early diagnosis and timely intervention and effective care become critical. The use of electronic medical record data to build an AKI risk prediction model has been proven to help prevent the occurrence of AKI. However, in actual clinical applications, the distribution of historical data and new data will continue to vary over time, resulting in a significant decrease in the performance of the model. How to solve the problem of model performance degradation over time will be a core challenge for the long-term use of predictive models in clinical applications. Aiming at the above problems, this paper studies the classic Transfer-Stacking model migration algorithm. Aiming at the lack of this algorithm, such as the loss of a large amount of feature information of the target domain and poor fit when integrating the model of the target domain, the Accumulate-Transfer-Stacking algorithm is proposed to improve it. Improvements include: 1) Optimize the input vector and model integration algorithm of Transfer-Stacking’s target domain model. 2) Optimize Transfer-Stacking from a single-source domain model to a multi-source domain model. The experimental results show that for the improved algorithm proposed in this paper when the data is sufficient and insufficient, the average AUC value of the model on the data of subsequent years is 0.89 and 0.87, and the average F1 Score value is 0.45 and 0.36. Moreover, this method is significantly better than the unimproved Transfer-Stacking algorithm and baseline method, and can effectively overcome the problem of data distribution heterogeneity caused by time factors. 展开更多
关键词 Acute Kidney Injury Electronic Medical Record Risk Prediction Transfer Learning
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Transfer-Learning for Automated Seizure Detection Based on Electric Field Encephalography Reconstructed Signal
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作者 Gefei Zhu 《Communications and Network》 2020年第4期174-198,共25页
Building an automatic seizure onset prediction model based on multi-channel electroencephalography (EEG) signals has been a hot topic in computer science and neuroscience field for a long time. In this research, we co... Building an automatic seizure onset prediction model based on multi-channel electroencephalography (EEG) signals has been a hot topic in computer science and neuroscience field for a long time. In this research, we collect EEG data from different epilepsy patients and EEG devices and reconstruct and combine the EEG signals using an innovative electric field encephalography (EFEG) method, which establishes a virtual electric field vector, enabling extraction of electric field components and increasing detection accuracy compared to the conventional method. We extract a number of important features from the reconstructed signals and pass them through an ensemble model based on support vector machine (SVM), Random Forest (RF), and deep neural network (DNN) classifiers. By applying this EFEG channel combination method, we can achieve the highest detection accuracy at 87% which is 6% to 17% higher than the conventional channel averaging combination method. Meanwhile, to reduce the potential overfitting problem caused by DNN models on a small dataset and limited training patient, we ensemble the DNN model with two “weaker” classifiers to ensure the best performance in model transferring for different patients. Based on these methods, we can achieve the highest detection accuracy at 82% on a new patient using a different EEG device. Thus, we believe our method has good potential to be applied on different commercial and clinical devices. 展开更多
关键词 EEG Seizure Detection Transfer Learning Deep Neural Network Electric Field Encephalography
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TRANSFER-MATRIX METHOD FOR SURFACE SPIN WAVES IN A SEMI-INFINITE MAGNETIC SUPERLATTICE WITH A SINGLE-ION ANISOTROPY
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作者 李振亚 沈文忠 《苏州大学学报(自然科学版)》 CAS 1992年第2期176-184,共9页
Surface spin waves in a semi-infinite magnetre super lattice with a single-ion uniaxial anisotropy are investigated through the transfer mafrix method.The dispersion equations of surface spin wavs are obfained.We find... Surface spin waves in a semi-infinite magnetre super lattice with a single-ion uniaxial anisotropy are investigated through the transfer mafrix method.The dispersion equations of surface spin wavs are obfained.We find that not all the magnetic superlattice structures can excite the surface spin waves,and that the anisotropy term need not be favorable to the excitation of surface spin wavs,but surely influences the values of the energy of the excited surface spin waves. 展开更多
关键词 转移矩阵法 表面旋转波 超点阵 磁性材料 各向异性 离子
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对流传热区局部对流传热强度参数及其与机械能耗散关系研究综述 被引量:1
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作者 王良璧 介云飞 +2 位作者 卢鑫 朱实强 郭安宁 《兰州交通大学学报》 2026年第1期1-6,共6页
对流传热是与工业、环境、动植物生命、宇宙等息息相关的热量传输过程。就工业生产而言,对流传热过程消耗了大量高品位能源,造成了大量的碳排量,从而研究对流传热强化对节能减排非常重要。对流传热过程机械能耗散在流动局部进行,而对流... 对流传热是与工业、环境、动植物生命、宇宙等息息相关的热量传输过程。就工业生产而言,对流传热过程消耗了大量高品位能源,造成了大量的碳排量,从而研究对流传热强化对节能减排非常重要。对流传热过程机械能耗散在流动局部进行,而对流传热强度只有在壁面上存在,从而需一局部对流传热强度的描述参数以便和局部机械能耗散对应,这一对应是对流传热强化的基础。论文对现有类似对流传热区局部对流传热强度的描述参数及其与机械能耗散的关系进行了综述,在此基础上提出对流传热区局部对流传热强度的描述参数及其与机械能耗散的关系的研究思路。 展开更多
关键词 对流传热 局部对流传热强度 局部机械能耗散
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肉羊超数排卵及胚胎移植技术应用效果分析
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作者 王晶晶 刘昱成 +4 位作者 郭延华 倪建宏 刘长彬 傅祥伟 万鹏程 《家畜生态学报》 北大核心 2026年第2期75-79,共5页
为探究肉羊同期发情超数排卵及胚胎移植效果,研究采用3种不同梯度促卵泡素(FSH)激素方案对45只白头杜泊母羊进行同期发情和超数排卵处理,筛选最优方案,对白头杜泊羊、黑头杜泊羊和多胎萨福克羊各20只进行超数排卵,探究黄体存在或缺失对... 为探究肉羊同期发情超数排卵及胚胎移植效果,研究采用3种不同梯度促卵泡素(FSH)激素方案对45只白头杜泊母羊进行同期发情和超数排卵处理,筛选最优方案,对白头杜泊羊、黑头杜泊羊和多胎萨福克羊各20只进行超数排卵,探究黄体存在或缺失对不同品种绵羊超数排卵反应和胚胎产量的影响,比较自然交配、宫颈输精和腹腔镜输精的受精率,并进行鲜胚和冻胚移植对比分析,旨在优化输精技术与胚胎移植技术体系。结果表明,3种方案的可用胚胎数均在88%以上,方案2只均冲胚数显著高于方案3(P<0.05),但只均可用胚胎数3组间无显著差异(P>0.05);白头杜泊羊、多胎萨福克羊的黄体数显著高于黑头杜泊羊黄体数(P<0.05),而卵巢黄体数量与胚胎存活率无显著相关性(P>0.05);腹腔镜输精技术受胎率优于自然交配、宫颈口人工授精受胎率(P<0.05);鲜胚组胚胎移植受胎率(67.93%)高于冻胚组(55.65%)(P<0.05)。综上所述,在本实验条件下,采用方案2(FSH总剂量400 IU,递减注射40~70 IU/次)对肉羊进行超排处理后,结合腹腔镜鲜胚移植技术,可显著提升胚胎移植效率。 展开更多
关键词 肉羊 超数排卵 胚胎 胚胎移植
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公交换乘优惠政策下居民换乘意向的异质性分析
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作者 马壮林 毕宇明 +2 位作者 周备 邓亚娟 兆雪 《吉林大学学报(工学版)》 北大核心 2026年第1期158-169,共12页
为探究公交换乘优惠政策下城市居民换乘意向的影响因素及其相互作用机理,本文在计划行为理论和技术接受模型的基础上融入行为习惯,采用结构方程模型(SEM)构建了公交换乘优惠政策下的居民换乘意向模型;采用显示性偏好(RP)方法设计调查问... 为探究公交换乘优惠政策下城市居民换乘意向的影响因素及其相互作用机理,本文在计划行为理论和技术接受模型的基础上融入行为习惯,采用结构方程模型(SEM)构建了公交换乘优惠政策下的居民换乘意向模型;采用显示性偏好(RP)方法设计调查问卷,通过网络调查获得365份有效样本,探究各心理潜变量之间的路径关系,并通过Bootstrap法检验模型的中介效应;采用单因素方差分析(ANOVA)探讨潜变量在不同群组中的异质性。结果表明:态度、主观规范、感知有用性和行为习惯对换乘意向有直接的显著影响;态度、感知有用性和感知易用性是中介变量,但并非在所有路径中都能发挥中介效应;潜变量对换乘意向影响的总效应值从大到小排序为:行为习惯(0.457)、感知有用性(0.366)、态度(0.326)、主观规范(0.312)、感知易用性(0.096);不同社会经济属性和出行特征的群组对潜变量的感知及影响存在显著差异。研究成果不仅有助于完善行为意向研究的理论体系,而且可为其他城市交通管理部门制定公交换乘优惠政策提供理论支撑。 展开更多
关键词 交通运输系统工程 公交换乘优惠政策 结构方程模型 换乘意向 计划行为理论 技术接受模型 行为习惯
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Spar钻井生产储卸油平台储油舱油水置换传热的特性数值模拟研究
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作者 韩盼盼 仝哲 +1 位作者 尤云祥 王晋 《哈尔滨工程大学学报》 北大核心 2026年第1期106-113,共8页
油水置换传热问题是制约深水立柱式Spar钻井生产储卸油平台推广应用的主要堵点之一。该平台是近年提出的一种新型海洋平台概念,将经典式Spar平台的水下立柱主体设计为湿式储油舱,并采用油水置换工艺进行储卸油操作。由于热油与海水直接... 油水置换传热问题是制约深水立柱式Spar钻井生产储卸油平台推广应用的主要堵点之一。该平台是近年提出的一种新型海洋平台概念,将经典式Spar平台的水下立柱主体设计为湿式储油舱,并采用油水置换工艺进行储卸油操作。由于热油与海水直接接触,在油水界面处将发生热量传输。另外,热油也将通过舱壁向外界释放热量。当热油温度低于其凝点时,将在油水界面处及舱壁内表面处形成凝油层,由此阻塞储油舱,影响油水置换工艺的顺利进行。特别地,当原油密度受温度影响不大时,油水置换储油舱内的温度分布将难以用简单的数学表达式表示。为此,针对该种原油,通过数值模拟方法定量分析油水置换储油舱内的速度场及温度场特性。研究发现,当储油舱尺度增大时,油水界面处的整体温度更高,舱壁凝油层的厚度更小;当储油舱舱壁的表面换热系数小于200 W(/m^(2)·K)时,油水界面处的最高温度迅速升高,壁面凝油厚度迅速减小。 展开更多
关键词 SDPSO平台 湿式储油 油水置换 传热特性 尺度效应 表面换热系数 凝油层
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金字塔型内表面太阳能集热管的传热性能的数值研究
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作者 林志敏 张航敏 +2 位作者 王朝霞 侯博 王良璧 《太阳能学报》 北大核心 2026年第1期146-157,共12页
为改善槽式太阳能集热管因非均匀受热引起的较大周向温差问题,通过冲压工艺在传统金属集热管内壁加工出金字塔型内表面集热管,并采用数值模拟方法,对比分析金字塔粗糙元不同长度比、宽度比、高度比对管内流动与传热特性、集热管周向最... 为改善槽式太阳能集热管因非均匀受热引起的较大周向温差问题,通过冲压工艺在传统金属集热管内壁加工出金字塔型内表面集热管,并采用数值模拟方法,对比分析金字塔粗糙元不同长度比、宽度比、高度比对管内流动与传热特性、集热管周向最大温差、二次流强度以及局部传热特性的影响。研究结果表明:金字塔型粗糙元的引入提高了传统集热管的换热能力,其结构参数会不同程度地影响流动与传热特性,最大强化传热因子达1.59。与传统集热管相比,金字塔型强化管周向最大温差降幅最高可达51.68%。此外,局部努塞尔数(Nulocal)在周向上呈周期性变化规律,在金字塔粗糙元的塔尖和塔底之间出现峰值。截面平均努塞尔数(Nuz)与二次流强度(Sez)沿流动方向的变化趋势一致,同时,Num和Se随雷诺数(Re)的变化趋势也保持一致,表明金字塔型内表面管内二次流强度决定其换热强度。 展开更多
关键词 太阳能集热器 传热 二次流 阻力系数 数值模拟
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频域增强自适应通道注意力与特征金字塔融合的可逆流网络风格迁移
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作者 葛斌 邵孜绎 +3 位作者 郑军帅 夏晨星 官骏鸣 徐涛 《模式识别与人工智能》 北大核心 2026年第1期83-96,共14页
针对风格迁移中内容失真、出现伪影与频域特性利用不足的问题,文中提出基于频域增强自适应通道注意力与特征金字塔融合的可逆流网络风格迁移方法.首先,以预训练VGG19为基础架构,设计可逆流网络,利用无偏差特征传递机制减少特征损耗,保... 针对风格迁移中内容失真、出现伪影与频域特性利用不足的问题,文中提出基于频域增强自适应通道注意力与特征金字塔融合的可逆流网络风格迁移方法.首先,以预训练VGG19为基础架构,设计可逆流网络,利用无偏差特征传递机制减少特征损耗,保障内容结构的完整性.然后,设计频域增强自适应通道注意力模块,解析风格图像频域分布,建立内容特征与风格特征的精准关联,提升风格化效果.最后,构建特征金字塔融合模块,对齐全局风格与局部纹理,提升迁移结果协调性.在MS-COCO、WikiArt数据集上的实验表明,文中方法能平衡风格传递与内容保留,在内容结构完整性、风格化效果及计算效率上均较优. 展开更多
关键词 计算机视觉 深度学习 风格迁移 自注意力机制
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羊体细胞核移植技术研究进展及其应用
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作者 华再东 陈盈 +2 位作者 张年 郭帅 熊琪 《中国畜牧兽医》 北大核心 2026年第1期119-126,共8页
体细胞核移植(somatic cell nuclear transfer,SCNT)技术作为20世纪发育生物学领域的重大突破,其里程碑式成果是首例克隆哺乳动物多利羊的诞生,开创了哺乳动物克隆技术的新纪元。该技术通过将高度分化的体细胞核移植至去核卵母细胞,利... 体细胞核移植(somatic cell nuclear transfer,SCNT)技术作为20世纪发育生物学领域的重大突破,其里程碑式成果是首例克隆哺乳动物多利羊的诞生,开创了哺乳动物克隆技术的新纪元。该技术通过将高度分化的体细胞核移植至去核卵母细胞,利用卵胞质重编程能力实现细胞核重编程,最终发育为遗传背景一致的完整个体。笔者系统综述了克隆羊研究的科学历程、关键技术优化及其重要应用价值,重点叙述了供体细胞选择与处理、核移植效率提升策略、表观遗传重编程分子机制及卵母细胞微环境调控等核心科学问题的研究进展,并探讨了该技术在畜牧品种快速扩繁、濒危物种保护、人类疾病模型构建以及治疗性克隆等生物医学领域的应用前景,进一步对未来技术发展方向进行展望,以期为SCNT技术的深入研究与产业化应用提供理论和实践参考。 展开更多
关键词 绵羊 体细胞核移植 核重编程 表观遗传调控
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仿真数据驱动的感应电动机定转子故障迁移识别方法
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作者 王攀攀 王宇佩 +3 位作者 张成 刘扬 戴诗科 韩丽 《中国电机工程学报》 北大核心 2026年第5期2080-2091,I0028,共13页
在工程实际中,感应电动机故障数据的匮乏已成为制约数据驱动诊断方法广泛应用于现场实际的瓶颈。为了摆脱对实际数据的依赖,提出一种基于仿真数据驱动的感应电动机定转子故障迁移诊断方法。首先,通过有限元建模,产生电机不同健康状态下... 在工程实际中,感应电动机故障数据的匮乏已成为制约数据驱动诊断方法广泛应用于现场实际的瓶颈。为了摆脱对实际数据的依赖,提出一种基于仿真数据驱动的感应电动机定转子故障迁移诊断方法。首先,通过有限元建模,产生电机不同健康状态下的电压和电流数据;然后,分析不同故障在瞬时功率中的表现,并将其中不同频率的故障特征分量转化为不同颜色的轨迹图形,进而形成多特征分量融合的图形化样本,用以降低仿真数据与实际数据间的分布差异,达到降低迁移识别难度的目的;最后,以该图形化样本作为输入,将仿真数据训练后的卷积神经网络直接应用于实际电机的故障辨识。实验结果表明,该方法在只学习仿真数据样本的情况下,仍能准确辨识出实际电机的定转子故障,且准确率高达97.7%,满足工程要求。 展开更多
关键词 感应电动机 迁移学习 定转子故障 图形化样本 卷积神经网络
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基于LBM的油气藏开发流固共轭传热微观机理研究
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作者 张洋 侯健 +3 位作者 韦贝 刘海湖 吴光焕 王传飞 《力学学报》 北大核心 2026年第2期528-541,共14页
多孔介质内的流固共轭传热现象在地热开发、稠油热采、水合物热激开发等能源利用过程中广泛存在.由于流体的导热性质和岩石的导热性质差异较大,主要传热方式不同,流固界面处的传热机制十分复杂.为从微观本质上认清储层多孔介质内的共轭... 多孔介质内的流固共轭传热现象在地热开发、稠油热采、水合物热激开发等能源利用过程中广泛存在.由于流体的导热性质和岩石的导热性质差异较大,主要传热方式不同,流固界面处的传热机制十分复杂.为从微观本质上认清储层多孔介质内的共轭传热机理,建立了考虑流固共轭传热的格子玻尔兹曼(LBM)模拟方法,分析了共轭传热特征和储层能量变化规律,并探究了岩石、流体性质和多孔介质结构对传热效果的影响.模拟结果表明:在局部非热平衡条件下,佩克莱数降低或热扩散系数比增大有利于注入能量在储层内得到有效利用;而在相同注入能量下,岩石与流体吸收的能量均随佩克莱数与热扩散系数比增大而增加;热损失随顶底层岩石导热系数增大和储层有效厚度减小而加剧;储层有效导热系数随孔隙度和界面粗糙度增大而减小,随岩石/流体导热系数比增大而增大;注入介质中加入泡沫可使热前缘推进更加均匀,加入氮气可减小储层上部有效导热系数以实现保温.本研究可为油气藏开发中注入工艺优化、储层保温策略制定及注入介质优选等提供理论依据,对提高能源开发效益具有重要意义. 展开更多
关键词 多孔介质 格子玻尔兹曼方法 局部非热平衡 共轭传热
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基于弹簧-质量-阻尼模型的单环闭式脉动热管传热特性
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作者 战洪仁 刘德彬 +4 位作者 王立鹏 刘东灵 纪柏辰 刘鹏 吴旻 《化学工程》 北大核心 2026年第2期45-50,共6页
为探究单环闭式脉动热管的传热性能,使用理论推导获得脉动热管内两液柱系统振动方程,建立一个考虑气液相变的单环闭式脉动热管液柱振荡运动的弹簧-质量-阻尼模型。基于该模型,得到在弹性系数、质量等参数发生非线性变化下的单环闭式脉... 为探究单环闭式脉动热管的传热性能,使用理论推导获得脉动热管内两液柱系统振动方程,建立一个考虑气液相变的单环闭式脉动热管液柱振荡运动的弹簧-质量-阻尼模型。基于该模型,得到在弹性系数、质量等参数发生非线性变化下的单环闭式脉动热管的传热特性。并进行实验研究,验证该数学模型的正确性。结果表明:充液率为60%、加热功率为60 W时,脉动热管传热性能最好。脉动热管的启动时间与混沌特性呈正相关,混沌特性与传热特性呈正相关。 展开更多
关键词 弹簧-质量-阻尼模型 振动方程 非线性 传热性能 混沌特性
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