期刊文献+
共找到16,628篇文章
< 1 2 250 >
每页显示 20 50 100
Structure variation of cadmium naphthalene⁃diphosphonates with the changing rigidity of N⁃donor auxiliary ligands
1
作者 XU Yan LI Suzhi +3 位作者 LI Yan FENG Lushun SUN Wentao LI Xinxing 《无机化学学报》 北大核心 2025年第2期395-406,共12页
Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-d... Five cadmium naphthalene-diphosphonates,formulated as[Cd_(1.5)(1,4-ndpaH_(2))2(4,4'-bpyH)(4,4'-bpy)0.5(H_(2)O)_(2)]2(1),[Cd(1,4-ndpaH_(2))(1,4-bib)0.5(H_(2)O)](2),[Cd(1,4-ndpaH3)2(1,2-dpe)(H_(2)O)]·(1,2-dpe)·7H_(2)O(3),(1,2-bixH)[Cd3(1,4-ndpaH)(1,4-ndpaH_(2))2(H_(2)O)_(2)](4),and[Cd(1,4-ndpaH_(2))(H_(2)O)]·H_(2)O(5),have been synthesized from the selfassembly reactions of 1,4-naphthalenediphosphonic acid(1,4-ndpaH4)with Cd(NO3)2·4H_(2)O by introducing auxiliary ligands with variation of rigidity,such as 4,4'-bipyridine(4,4'-bpy),1,4-bis(1-imidazolyl)benzene(1,4-bib),1,2-di(4-pyridyl)ethylene(1,2-dpe),1,3-di(4-pyridyl)propane(1,3-dpp),and bis(imidazol-1-ylmethyl)benzene(1,2-bix),respectively.Structure resolution by single-crystal X-ray diffraction reveals that compound 1 possesses a layered framework,in which the{Cd3(PO2)2}trimers made up of corner-sharing two{CdO4N2}and one{CdO6}octahedra are connected by phosphonate groups,forming a ribbon,which are cross-linked by 4,4'-bipy ligands,forming a 2D layer.Compound 2 shows a 3D open-framework structure,where chains of corner-sharing{CdO4N}trigonal bipyramids and{PO3C}tetrahedra are cross-linked by 1,4-bib and/or phosphonate groups.A 1D ladder-like chain structure is found in compound 3,where the ladder-like chains made up of corner-sharing{CdO5N}octahedra and{PO3C}tetra hedra are connected by 1,4-ndpaH_(2)^(2-).Both compounds 4 and 5 obtained by the introduction of flexible ligands during the synthesis show a 2D layered structure,which is formed by ligand crosslinking double metal chains.Interestingly,In 4,flexible 1,2-bix was singly protonated,as guest molecules,filled between layer and layer,while flexible ligand 1,3-dpp is absent in 5.Photophysical measurements indicate that compounds 1-5 show ligand-centered emissions. 展开更多
关键词 naphthalene diphosphate N-donor auxiliary ligands crystal structure RIGIDITY flexibility
下载PDF
Unsupervised Meteorological Downscaling Based on Dual Learning and Subgrid-scale Auxiliary Information
2
作者 Jing HU Jialing MU +1 位作者 Xiaomeng HUANG Xi WU 《Advances in Atmospheric Sciences》 2025年第1期53-66,共14页
Climate downscaling is used to transform large-scale meteorological data into small-scale data with enhanced detail,which finds wide applications in climate modeling,numerical weather forecasting,and renewable energy.... Climate downscaling is used to transform large-scale meteorological data into small-scale data with enhanced detail,which finds wide applications in climate modeling,numerical weather forecasting,and renewable energy.Although deeplearning-based downscaling methods effectively capture the complex nonlinear mapping between meteorological data of varying scales,the supervised deep-learning-based downscaling methods suffer from insufficient high-resolution data in practice,and unsupervised methods struggle with accurately inferring small-scale specifics from limited large-scale inputs due to small-scale uncertainty.This article presents DualDS,a dual-learning framework utilizing a Generative Adversarial Network–based neural network and subgrid-scale auxiliary information for climate downscaling.Such a learning method is unified in a two-stream framework through up-and downsamplers,where the downsampler is used to simulate the information loss process during the upscaling,and the upsampler is used to reconstruct lost details and correct errors incurred during the upscaling.This dual learning strategy can eliminate the dependence on high-resolution ground truth data in the training process and refine the downscaling results by constraining the mapping process.Experimental findings demonstrate that DualDS is comparable to several state-of-the-art deep learning downscaling approaches,both qualitatively and quantitatively.Specifically,for a single surface-temperature data downscaling task,our method is comparable with other unsupervised algorithms with the same dataset,and we can achieve a 0.469 dB higher peak signal-to-noise ratio,0.017 higher structural similarity,0.08 lower RMSE,and the best correlation coefficient.In summary,this paper presents a novel approach to addressing small-scale uncertainty issues in unsupervised downscaling processes. 展开更多
关键词 DOWNSCALING UNSUPERVISED deep learning dual learning auxiliary information
下载PDF
Numerical Study of Steam-Water Separators with Wave-type Vanes 被引量:13
3
作者 李嘉 黄素逸 王晓墨 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第4期492-498,共7页
Droplet behavior in the wave-type flow channel is discussed, especially with the secondary .droplet generation due to impingement of droplets on the wall considered. A numerical method is suggested to simulate tile dr... Droplet behavior in the wave-type flow channel is discussed, especially with the secondary .droplet generation due to impingement of droplets on the wall considered. A numerical method is suggested to simulate tile droplet behavior in the flow field. Calculations are compared With experimental data on the ; pressure drop and separating efficiency. Good agreement exists between the calculations and air-water experiments. The numerical method developed gives a reasonable description of the droplet deposition and secondary droplet generation, and it can be applied to predict the performance of wave-type vane separators. 展开更多
关键词 wave-type vanes steam-water separator multiphase flow
下载PDF
Ascertaining the influences of auxiliary qubits on the Einstein–Podolsky–Rosen steering and its directions
4
作者 邢玲玲 杨欢 +1 位作者 张刚 孔敏 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期213-221,共9页
Einstein–Podolsky–Rosen(EPR) steering is an example of nontrivial quantum nonlocality and characteristic in the non-classical world.The directivity(or asymmetry) is a fascinating trait of EPR steering,and it is diff... Einstein–Podolsky–Rosen(EPR) steering is an example of nontrivial quantum nonlocality and characteristic in the non-classical world.The directivity(or asymmetry) is a fascinating trait of EPR steering,and it is different from other quantum nonlocalities.Here,we consider the strategy in which two atoms compose a two-qubit X state,and the two atoms are owned by Alice and Bob,respectively.The atom of Alice suffers from a reservoir,and the atom of Bob couples with a bit flip channel.The influences of auxiliary qubits on EPR steering and its directions are revealed by means of the entropy uncertainty relation.The results indicate that EPR steering declines with growing time t when adding fewer auxiliary qubits.The EPR steering behaves as damped oscillation when introducing more auxiliary qubits in the strong coupling regime.In the weak coupling regime,the EPR steering monotonously decreases as t increases when coupling auxiliary qubits.The increases in auxiliary qubits are responsible for the fact that the steerability from Alice to Bob(or from Bob to Alice) can be more effectively revealed.Notably,the introductions of more auxiliary qubits can change the situation that steerability from Alice to Bob is certain to a situation in which steerability from Bob to Alice is certain. 展开更多
关键词 auxiliary qubits EPR steering DIRECTIONS influence
下载PDF
A new adaptive co-site broadband interference cancellation method with auxiliary channel
5
作者 Yunhao Jiang Siqi Liu +2 位作者 Minyang Li Nan Zhao Minghu Wu 《Digital Communications and Networks》 SCIE CSCD 2024年第4期934-947,共14页
With the boom of the communication systems on some independent platforms(such as satellites,space stations,airplanes,and vessels),co-site interference is becoming prominent.The adaptive interference cancellation metho... With the boom of the communication systems on some independent platforms(such as satellites,space stations,airplanes,and vessels),co-site interference is becoming prominent.The adaptive interference cancellation method has been adopted to solve the co-site interference problem.But the broadband interference cancellation performance of traditional Adaptive Co-site Interference Cancellation System(ACICS)with large delay mismatching and antenna sway is relatively poor.This study put forward an Adaptive Co-site Broadband Interference Cancellation System With Two Auxiliary Channels(ACBICS-2A).The system model was established,and the steady state weights and Interference Cancellation Ratio(ICR)were deduced by solving a time-varying differential equation.The relationship of ICR,system gain,modulation factor,interference signal bandwidth and delay mismatching degree was acquired through an in-depth analysis.Compared with traditional adaptive interference cancellation system,the proposed ACBICS-2A can improve broadband interference cancellation ability remarkably with large delay mismatching and antenna sway for the effect of auxiliary channel.The maximum improved ICR is more than 25 dB.Finally,the theoretical and simulation results were verified by experiments. 展开更多
关键词 Co-site broadband interference Interference cancellation auxiliary channel Delay mismatching
下载PDF
A GENERALIZED SCALAR AUXILIARY VARIABLE METHOD FOR THE TIME-DEPENDENT GINZBURG-LANDAU EQUATIONS
6
作者 司智勇 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期650-670,共21页
This paper develops a generalized scalar auxiliary variable(SAV)method for the time-dependent Ginzburg-Landau equations.The backward Euler method is used for discretizing the temporal derivative of the time-dependent ... This paper develops a generalized scalar auxiliary variable(SAV)method for the time-dependent Ginzburg-Landau equations.The backward Euler method is used for discretizing the temporal derivative of the time-dependent Ginzburg-Landau equations.In this method,the system is decoupled and linearized to avoid solving the non-linear equation at each step.The theoretical analysis proves that the generalized SAV method can preserve the maximum bound principle and energy stability,and this is confirmed by the numerical result,and also shows that the numerical algorithm is stable. 展开更多
关键词 time-dependent Ginzburg-Landau equation generalized scalar auxiliary variable algorithm maximum bound principle energy stability
下载PDF
Research on uninterruptable power supply technology for auxiliary winding of electric locomotive while passing the neutral section
7
作者 Yuliang Du 《Railway Sciences》 2024年第2期128-142,共15页
Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of t... Purpose–Auxiliary power system is an indispensable part of the train;the auxiliary systems of both electric locomotives and EMUs mainly are powered by one of the two ways,which are either from auxiliary windings of traction transformers or from DC-link voltage of traction converters.Powered by DC-link voltage of traction converters,the auxiliary systems were maintained of uninterruptable power supply with energy from electric braking.Meanwhile,powered by traction transformers,the auxiliary systems were always out of power while passing the neutral section of power supply grid and control system is powered by battery at this time.Design/methodology/approach–Uninterrupted power supply of auxiliary power system powered by auxiliary winding of traction transformer was studied.Failure reasons why previous solutions cannot be realized are analyzed.An uninterruptable power supply scheme for the auxiliary systems powered by auxiliary windings of traction transformers is proposed in this paper.The validity of the proposed scheme is verified by simulation and experimental results and on-site operation of an upgraded HXD3C type locomotive.This scheme is attractive for upgrading practical locomotives with the auxiliary systems powered by auxiliary windings of traction transformers.Findings–This scheme regenerates braking power supplied to auxiliary windings of traction transformers while a locomotive runs in the neutral section of the power supply grid.Control objectives of uninterrupted power supply technology are proposed,which are no overvoltage,no overcurrent and uninterrupted power supply.Originality/value–The control strategies of the scheme ensure both overvoltage free and inrush current free when a locomotive enters or leaves the neutral section.Furthermore,this scheme is cost low by employing updated control strategy of software and add both the two current sensors and two connection wires of hardware. 展开更多
关键词 Electric locomotive auxiliary system Neutral section Uninterruptable power supply OVERVOLTAGE Inrush current
下载PDF
2024 National Practical Technical Training on Textile Printing and Dyeing Auxiliary Preparation Succeeds
8
《China Detergent & Cosmetics》 CAS 2024年第3期79-79,共1页
From July 16th to 19th,2024,2024 National Practical Technical Training on Textile Printing and Dyeing Auxiliary Preparation,organized by China Research Institute of Daily Chemical and National Engineering Research Cen... From July 16th to 19th,2024,2024 National Practical Technical Training on Textile Printing and Dyeing Auxiliary Preparation,organized by China Research Institute of Daily Chemical and National Engineering Research Center for Surfactants,and co-organized by the Dyeing and Finishing Technology Research Institute of Zhejiang Fashion Institute of Technology and the High Fastness Plant-based Dye Research Base of China Textile Engineering Society,was held successfully in Shangyu,Zhejiang Province,with 92 representatives from 64 work units from all over China. 展开更多
关键词 auxiliary China TRAINING
下载PDF
Auxiliary Software for Defining the Parameters of the Structural Organization of a Complex System
9
作者 Branislav M. Savic 《Journal of Software Engineering and Applications》 2024年第2期109-128,共20页
The developed auxiliary software serves to simplify, standardize and facilitate the software loading of the structural organization of a complex technological system, as well as its further manipulation within the pro... The developed auxiliary software serves to simplify, standardize and facilitate the software loading of the structural organization of a complex technological system, as well as its further manipulation within the process of solving the considered technological system. Its help can be especially useful in the case of a complex structural organization of a technological system with a large number of different functional elements grouped into several technological subsystems. This paper presents the results of its application for a special complex technological system related to the reference steam block for the combined production of heat and electricity. 展开更多
关键词 Complex System Structural Organization auxiliary Software PARAMETERS
下载PDF
弹目交会条件下爆炸驱动结构体的展开过程研究
10
作者 宁建国 汪齐 栗建桥 《高压物理学报》 CAS 北大核心 2025年第1期1-16,共16页
复杂结构在爆炸驱动作用下的展开是展开型定向战斗部定向过程中的关键问题,对展开过程进行有效控制,有利于战斗部的起爆延时控制和破片利用率提高。针对复杂结构体的展开问题,基于JWL状态方程和第二类拉格朗日方程,从能量守恒出发推导... 复杂结构在爆炸驱动作用下的展开是展开型定向战斗部定向过程中的关键问题,对展开过程进行有效控制,有利于战斗部的起爆延时控制和破片利用率提高。针对复杂结构体的展开问题,基于JWL状态方程和第二类拉格朗日方程,从能量守恒出发推导了考虑爆轰产物膨胀过程和对目标命中状态的爆炸驱动展开模型。将驱动展开模型计算结果与文献实验结果进行对比,验证了爆炸驱动展开模型计算结果的准确性。结果表明,基于该模型的理论计算结果与实验结果的一致性较好,能较为精确地预测不同装药量下结构的展开时间;将辅助装药1与辅助装药2的质量比控制在1.5~1.7,结构体展开可达最佳命中姿态,更有利于命中目标。研究成果可充实定向战斗部设计理论,为展开型定向战斗部的设计提供参考。 展开更多
关键词 爆炸驱动 展开姿态 展开时间 辅助装药 定向战斗部
下载PDF
BDC-DAL:基于蓝图差分卷积和双重辅助监督的轻量化人脸活体检测算法
11
作者 叶继华 梁芳昕 +3 位作者 王超 肖顺杰 宗义 江爱文 《浙江大学学报(理学版)》 北大核心 2025年第1期98-109,121,共13页
人脸活体检测是确保人脸识别系统安全不可或缺的一环。当前大多数人脸活体检测算法采用的是深度卷积神经网络,尽管其检测性能卓越,但往往涉及庞大的参数量和计算复杂度,限制了其应用。为克服这些挑战,提出了一种基于蓝图差分卷积和双重... 人脸活体检测是确保人脸识别系统安全不可或缺的一环。当前大多数人脸活体检测算法采用的是深度卷积神经网络,尽管其检测性能卓越,但往往涉及庞大的参数量和计算复杂度,限制了其应用。为克服这些挑战,提出了一种基于蓝图差分卷积和双重辅助监督的轻量级人脸活体检测算法(BDC-DAL)。通过将轻量化的卷积结构和蓝图差分卷积设计相结合,有效降低了模型的参数和计算量,同时保留了捕捉复杂细粒度特征的能力。此外,引入的双重辅助监督机制,利用监督信号重建过程学习细微的欺诈线索,显著提高了模型对未知攻击场景的鲁棒性。为验证算法的有效性,在CelebA-Spoof和OULU-NPU人脸活体检测数据集上进行了广泛测试,并与当前主流的深度学习人脸活体检测算法和其他轻量化网络模型进行了比较,实验结果显示,BDC-DAL算法大幅降低了模型复杂度,参数量减少了近90%,模型的浮点计算量也下降了约10%。BDC-DAL算法在实现高效性和轻量化的同时,成功平衡了性能与资源消耗,为在资源受限环境下的人脸识别提供了可行的解决方案。 展开更多
关键词 人脸活体检测 轻量级 辅助信息监督
下载PDF
瑞士乳杆菌LH43作为辅助发酵剂对酸奶品质和蛋白质构象的影响
12
作者 马岩 李玉星 李柏良 《食品科学》 北大核心 2025年第5期134-141,共8页
为了探究具有产高分子质量胞外多糖能力的瑞土乳杆菌LH43作为辅助发酵剂对酸奶的影响,本实验利用质构分析仪、流变仪、扫描电镜、核磁共振仪、荧光分光光度计和圆二色光谱分析酸奶的凝胶特性和蛋白质构象。结果表明,采用瑞士乳杆菌LH43... 为了探究具有产高分子质量胞外多糖能力的瑞土乳杆菌LH43作为辅助发酵剂对酸奶的影响,本实验利用质构分析仪、流变仪、扫描电镜、核磁共振仪、荧光分光光度计和圆二色光谱分析酸奶的凝胶特性和蛋白质构象。结果表明,采用瑞士乳杆菌LH43作为辅助发酵剂能够显著提升酸奶的质构特性、持水能力及流变特性,改善了酸奶的微观结构和风味特性。同时,该菌株还降低了酸奶蛋白质的表面疏水性、游离巯基含量及无规卷曲相对含量,并增加了α-螺旋结构的相对含量,这证实了α-螺旋和无规卷曲是导致发酵乳凝胶产生差异的内在因素。综上所述,瑞士乳杆菌LH43可用于改善乳制品的凝胶性能,本研究可为酸奶发酵工艺的发展提供新的参考。 展开更多
关键词 瑞士乳杆菌 辅助发酵剂 加工性质 蛋白质构象
下载PDF
还原氧化石墨烯/壳聚糖自组装棉织物的制备及性能
13
作者 付承臣 赖璐 +2 位作者 周培茹 赖红静 曹机良 《精细化工》 北大核心 2025年第1期197-202,214,共7页
首先,以乙二醛和壳聚糖(CS)对纯棉织物进行改性制备了CS改性棉织物;然后,将CS改性棉织物经氧化石墨烯(GO)分散液浸渍;最后,将吸附沉积在棉织物上的GO还原为还原氧化石墨烯(RGO),制备了RGO/CS-棉织物。采用SEM、FTIR和Raman光谱对其进行... 首先,以乙二醛和壳聚糖(CS)对纯棉织物进行改性制备了CS改性棉织物;然后,将CS改性棉织物经氧化石墨烯(GO)分散液浸渍;最后,将吸附沉积在棉织物上的GO还原为还原氧化石墨烯(RGO),制备了RGO/CS-棉织物。采用SEM、FTIR和Raman光谱对其进行了表征,考察了CS质量分数、GO分散液质量浓度对RGO/CS-棉织物导电、抗紫外线和抑菌性能的影响,并对其耐洗性进行了测试。结果表明,RGO/CS-棉织物表面沉积的GO已较充分还原为RGO,表面覆盖了一层连续的RGO/CS薄膜;RGO/CS-棉织物导电性随着GO分散液质量浓度的增加而逐渐增强;经质量分数2.00%的CS溶液改性和质量浓度5 g/L的GO分散液处理并还原后的RGO/CS-棉织物具有最佳的导电性,表面电阻为1.02 kΩ/cm;RGO与CS协同增强了RGO/CS-棉织物的抑菌性能,抑菌率最高达95%;经质量分数0.50%的CS溶液改性和质量浓度3 g/L的GO分散液处理并还原后的RGO/CS-棉织物经过30~50次皂洗洗涤后,导电、抑菌和抗紫外线性能变化较小。 展开更多
关键词 壳聚糖 氧化石墨烯 棉织物 导电 自组装 纺织染整助剂
下载PDF
基于射流瞬态流速变分模态分解法的纬纱波动幅度预测
14
作者 沈敏 欧阳灿 +4 位作者 熊小双 王真 杨学正 吕永法 余联庆 《纺织学报》 北大核心 2025年第1期187-196,共10页
为降低柔性纬纱在引纬过程中因辅助喷嘴高速气流曳力而产生过大形变,使用基于分解层数优化的变分模态分解(VMD)方法,获得辅助喷嘴射流瞬时速度信号的本征模态分量(IMF),利用IMF预测柔性纬纱运动形变,降低断纬率。首先采用大涡模拟(LES)... 为降低柔性纬纱在引纬过程中因辅助喷嘴高速气流曳力而产生过大形变,使用基于分解层数优化的变分模态分解(VMD)方法,获得辅助喷嘴射流瞬时速度信号的本征模态分量(IMF),利用IMF预测柔性纬纱运动形变,降低断纬率。首先采用大涡模拟(LES)方法数值模拟了圆锥形、圆弧形及圆柱形入口辅助喷嘴射流的瞬态流场分布,监测了辅助喷嘴射流在势核与势尾区域瞬态速度信号;继而,通过VMD方法,得到监测点速度的本征模态分量,讨论了各本征模态信号波动的方差,最后通过双向流固耦合法得到纬纱的径向偏移来验证预测的准确性。结果发现:3种辅助喷嘴势核与势尾处主模态IMF1速度幅值稳定,为辅助喷嘴的主速度模态;次模态IMF2波动大且与纬纱径向偏移具有同步性,可用于预测纬纱波动;第3模态IMF3为高频振荡信号,可视为流场高频噪声信号去除。 展开更多
关键词 喷气织机 辅助喷嘴射流 瞬态流场 大涡模拟 变分模态分解 纬纱波动
下载PDF
跨域水生病毒
15
作者 张奇亚 柯飞 《水生生物学报》 北大核心 2025年第1期61-75,共15页
水生病毒是感染各类水生生物或存在于不同水体中的病毒,为水生生态系统中最丰富的生物实体,显著影响宿主群落的结构与功能、从而影响生物圈和全球生物地球化学循环。无论从分类地位、宿主范围,还是遗传进化及生态效应角度来看,水生病毒... 水生病毒是感染各类水生生物或存在于不同水体中的病毒,为水生生态系统中最丰富的生物实体,显著影响宿主群落的结构与功能、从而影响生物圈和全球生物地球化学循环。无论从分类地位、宿主范围,还是遗传进化及生态效应角度来看,水生病毒都显示出丰富的多样性和跨域特征。以往对病毒感染及其影响的理解主要集中在病毒与宿主细胞的相互作用和其分子水平上。但要清晰认识水生病毒在生态系统中的作用及对生物地球化学循环的影响,则需结合微观、介观和宏观尺度,甚至遥感观测及多种新技术来实现。文章就跨域水生病毒与特征、驱动物种进化、病毒分流和地球化学循环效应及相关新兴技术等研究进展进行概述。 展开更多
关键词 水生病毒 病毒圈 生物地球化学循环 病毒分流 辅助代谢基因 水生态 病毒学新技术
下载PDF
考虑风电与光热电站参与能量-调频辅助服务市场的联合投标策略
16
作者 陈伟 刘文翰 +1 位作者 李万伟 冯智慧 《太阳能学报》 北大核心 2025年第1期402-411,共10页
针对高比例新能源接入电网导致电网调频需求增大的困局,提出风电和光热电站联合参与能量-调频市场的系统架构。为保证日前投标计划的精准执行,引入偏差惩罚机制,并考虑风电、光照幅度及市场价格的不确定性因素,以联合系统总收益最大为目... 针对高比例新能源接入电网导致电网调频需求增大的困局,提出风电和光热电站联合参与能量-调频市场的系统架构。为保证日前投标计划的精准执行,引入偏差惩罚机制,并考虑风电、光照幅度及市场价格的不确定性因素,以联合系统总收益最大为目标,提出基于鲁棒优化的日前-实时两阶段最优投标策略,通过仿真验证,证明了相比于风电、光热电站单独投标,联合投标可通过光热电站灵活的调节特性平抑风电波动造成的投标偏差惩罚,提升联合系统的整体收益。最后,分析不同能量和调频市场价格对联合系统投标收益的影响。 展开更多
关键词 电力市场 光热电站 风电 鲁棒优化 调频辅助服务 投标策略
下载PDF
智能化时代下的口腔黏膜病学——人工智能应用研究的现状与展望
17
作者 杨青默 魏攀 华红 《口腔医学研究》 北大核心 2025年第1期1-6,共6页
随着人工智能(artificial intelligence,AI)技术的发展,其在医学领域的融合应用受到广泛关注。医学人工智能在影像识别、疾病辅助诊断、疾病风险预测、提供健康咨询服务等方面发挥越来越重要的作用。口腔黏膜病诊断和评估高度依赖形态... 随着人工智能(artificial intelligence,AI)技术的发展,其在医学领域的融合应用受到广泛关注。医学人工智能在影像识别、疾病辅助诊断、疾病风险预测、提供健康咨询服务等方面发挥越来越重要的作用。口腔黏膜病诊断和评估高度依赖形态学特征,AI在该领域具有广阔的应用前景。本文针对AI在口腔黏膜病辅助诊断、风险预测中的应用进行综述,并对当前面临的挑战和未来发展趋势进行分析和展望,以期为口腔黏膜病AI未来相关研究提供参考。 展开更多
关键词 人工智能 深度学习 口腔黏膜病 辅助诊断 风险预测
下载PDF
Two Second-Order Ecient Numerical Schemes for the Boussinesq Equations
18
作者 LIU Fang WANG Danxia ZHANG Jianwen 《应用数学》 北大核心 2025年第1期114-129,共16页
In this paper,we construct two fully decoupled,second-order semi-discrete numerical schemes for the Boussinesq equations based on the scalar auxiliary variable(SAV)approach.By introducing a scalar auxiliary variable,t... In this paper,we construct two fully decoupled,second-order semi-discrete numerical schemes for the Boussinesq equations based on the scalar auxiliary variable(SAV)approach.By introducing a scalar auxiliary variable,the original Boussinesq system is transformed into an equivalent one.Then we discretize it using the second-order backward di erentiation formula(BDF2)and Crank-Nicolson(CN)to obtain two second-order time-advanced schemes.In both numerical schemes,a pressure-correction method is employed to decouple the velocity and pressure.These two schemes possess the desired property that they can be fully decoupled with satisfying unconditional stability.We rigorously prove both the unconditional stability and unique solvability of the discrete schemes.Furthermore,we provide detailed implementations of the decoupling procedures.Finally,various 2D numerical simulations are performed to verify the accuracy and energy stability of the proposed schemes. 展开更多
关键词 Scalar auxiliary variable approach Pressure-correction method Fully decoupled Unconditional stability Boussinesq equations
下载PDF
基于知识图谱的“编译原理”课程辅助教学应用
19
作者 郭逸帆 昝红英 +3 位作者 张俊祁 刘涛 张坤丽 徐江峰 《计算机应用文摘》 2025年第1期48-54,58,共8页
作为计算机专业的核心基础课程,“编译原理”主要介绍编译程序构造的基本原理和方法。针对“编译原理”课程知识点琐碎、难以系统掌握的问题,文章从编译原理教材文本出发,在调研已有课程知识图谱的基础上,以《程序设计语言编译原理》教... 作为计算机专业的核心基础课程,“编译原理”主要介绍编译程序构造的基本原理和方法。针对“编译原理”课程知识点琐碎、难以系统掌握的问题,文章从编译原理教材文本出发,在调研已有课程知识图谱的基础上,以《程序设计语言编译原理》教材的核心脉络为依托,提出了“编译原理”课程的实体标注规范,确立了课程知识图谱的实体及实体关系分类体系,并采用自顶向下的方法构建了“编译原理”课程知识图谱(Compilation Principle Course Knowledge Graph,CP-CKG)。首先,以“编译原理”课程体系为中心,依据专业术语标准和现有词汇表,制定了概念分类和关系描述体系,形成了CP-CKG的模式层。在此基础上,以JREwBART和PREwBART模型为工具,在编译原理领域专家的指导下,借助知识标注平台对非结构化文本进行了半自动标注和人工标注,最终构建了CP-CKG的数据层。基于所构建的知识图谱,实现了课程知识问答系统以及由此延伸的学生答疑论坛,为“编译原理”课程提供了结构化的知识基础,为课程教学和管理提供了有效的支持。未来,将进一步扩大CP-CKG的应用范围,并完善课程知识图谱的构建流程,以满足更多课程的辅助教学需求。 展开更多
关键词 编译原理 知识图谱 实体关系抽取 辅助教学
下载PDF
纤维素基光致变色水凝胶制备及织物应用性能
20
作者 张帆 毛钺程 +3 位作者 申路阳 蔡再生 徐群娜 马建中 《精细化工》 北大核心 2025年第1期203-214,共12页
以纤维素纳米晶(CNC)、羧甲基纤维素钠(CMC)、羟基螺吡喃(SP-OH)为原料,在环氧氯丙烷(ECH)交联作用下,制备了纤维素基光致变色水凝胶(CPHs),以CPHs为光致变色材料和织物整理剂,采用常规浸轧整理制备了光致变色棉织物(CPHs-浸轧)。采用F... 以纤维素纳米晶(CNC)、羧甲基纤维素钠(CMC)、羟基螺吡喃(SP-OH)为原料,在环氧氯丙烷(ECH)交联作用下,制备了纤维素基光致变色水凝胶(CPHs),以CPHs为光致变色材料和织物整理剂,采用常规浸轧整理制备了光致变色棉织物(CPHs-浸轧)。采用FTIR、SEM、EDS、UV-Vis吸收光谱对其进行了表征,考察了ECH用量(以CMC、CNC及SP-OH总质量计,下同)对CPHs稳定性、光致变色响应性和CPHs-浸轧的表面水润湿性、色牢度和耐光疲劳性的影响。结果表明,CPHs具有三维网络多孔结构。由ECH用量为15%制备的CPHs(命名为CPHs-15)具有更优异的光致变色能力、干燥-溶胀循环能力和较好的透明度,且结构稳定、外观完整。CPHs-15经紫外光照射后吸光度明显上升,光响应性在被照射约120 s时达到最大值;后经可见光照射后,CPHs-15逐渐褪色,吸光度明显下降,光响应在约180 s时达到最小值。CPHs-15的48 h溶胀率为1410%,干燥-溶胀循环次数为8次。CPHs-15-浸轧在紫外光及可见光照射下具有快速的光致变色响应性,在2~3 min内实现快速着色褪色,其皂洗前后均可以保证10次以上可逆循环变色;CPHs-15-浸轧与棉织物具有较强的亲和力,经紫外光照射变色后,水接触角为63.7°。 展开更多
关键词 纤维素 螺吡喃 光致变色 水凝胶 棉织物 纺织染整助剂
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部