期刊文献+
共找到10,342篇文章
< 1 2 250 >
每页显示 20 50 100
Towards intelligent and trustworthy task assignments for 5G-enabled industrial communication systems
1
作者 Mingfeng Huang Anfeng Liu +1 位作者 Neal N.Xiong Athanasios V.Vasilakos 《Digital Communications and Networks》 2025年第1期246-255,共10页
With the unprecedented prevalence of Industrial Internet of Things(IIoT)and 5G technology,various applications supported by industrial communication systems have generated exponentially increased processing tasks,whic... With the unprecedented prevalence of Industrial Internet of Things(IIoT)and 5G technology,various applications supported by industrial communication systems have generated exponentially increased processing tasks,which makes task assignment inefficient due to insufficient workers.In this paper,an Intelligent and Trustworthy task assignment method based on Trust and Social relations(ITTS)is proposed for scenarios with many tasks and few workers.Specifically,ITTS first makes initial assignments based on trust and social influences,thereby transforming the complex large-scale industrial task assignment of the platform into the small-scale task assignment for each worker.Then,an intelligent Q-decision mechanism based on workers'social relation is proposed,which adopts the first-exploration-then-utilization principle to allocate tasks.Only when a worker cannot cope with the assigned tasks,it initiates dynamic worker recruitment,thus effectively solving the worker shortage problem as well as the cold start issue.More importantly,we consider trust and security issues,and evaluate the trust and social circles of workers by accumulating task feedback,to provide the platform a reference for worker recruitment,thereby creating a high-quality worker pool.Finally,extensive simulations demonstrate ITTS outperforms two benchmark methods by increasing task completion rates by 56.49%-61.53%and profit by 42.34%-47.19%. 展开更多
关键词 Industrial Internet of Things Insufficient workers Trust evaluation Social relation Task assignment
在线阅读 下载PDF
反思债权让与中的通知对抗主义
2
作者 武腾 《云南社会科学》 北大核心 2026年第1期128-136,共9页
按照通知对抗主义,债权让与通知不仅是对抗债务人的要件,还是债权多重让与场合决定受让人之间优先性的要件,通知因此兼具保护债务人的功能和保护受让人的功能。然而,债务人的利益和受让人的利益并不一致,该模式造成债务人双重给付的风... 按照通知对抗主义,债权让与通知不仅是对抗债务人的要件,还是债权多重让与场合决定受让人之间优先性的要件,通知因此兼具保护债务人的功能和保护受让人的功能。然而,债务人的利益和受让人的利益并不一致,该模式造成债务人双重给付的风险增加,且债务人容易陷入道德困境。通知对抗主义试图在普通债权领域全面引入公示原则,忽视了普通债权与证券债权之间的分工。有价证券制度为克服普通债权缺少外观之弱点,提供了极具针对性的应对方案。为促进债权交易安全,应该更加重视有价证券制度的完善和适用,而非拘泥于对普通债权让与规则的重构。近年来,普通债权的融资实践中经常采取不通知债务人的做法,通知对抗主义无助于保障这些交易的顺利开展。普通债权让与一般规则仍然应该坚持合同生效主义。 展开更多
关键词 债权让与 通知对抗主义 合同生效主义 证券债权 将来债权
在线阅读 下载PDF
~1H and ^(13)C NMR Assignments for Amlodipine and Risperidone
3
作者 杨春晖 李勤 +2 位作者 刘雪辉 赵兴凯 崔育新 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第1期49-52,共4页
Aim To investigate the NMR spectroscopy of amlodipine and risperidone.Methods 1D NMR and 2D NMR experimental techniques of gCOSY, gHSQC and gHMBC were wsed. Results Theassignments of the ~1H and ^(13) C NMR data for t... Aim To investigate the NMR spectroscopy of amlodipine and risperidone.Methods 1D NMR and 2D NMR experimental techniques of gCOSY, gHSQC and gHMBC were wsed. Results Theassignments of the ~1H and ^(13) C NMR data for the two drugs were performed and confirmed by theevidence of J_(HF) and J_(CF). Conclusion The structures of amlodipine and risperidone wereconfirmed by careful analysis of regular 1D and 2D NMR spectroscopy. 展开更多
关键词 NMR ASSIGNMENT fluorine coupling AMLODIPINE RISPERIDONE
暂未订购
猪流行性腹泻病毒(GHN/HB01株)灭活病毒标准物质的研制
4
作者 房琳琳 张锋 +3 位作者 刘爽 魏荣 董雅琴 包静月 《中国兽医杂志》 北大核心 2026年第1期45-55,共11页
为提高猪流行性腹泻病毒(PEDV)核酸检测结果的准确性,本试验建立PEDV微滴式数字聚合酶链式反应(ddPCR)检测方法;制备PEDV(GHN/HB01株)灭活病毒标准物质,通过实时荧光定量PCR(qPCR)和PCR方法检测外源病原体以评价其纯净性;采用ddPCR方法... 为提高猪流行性腹泻病毒(PEDV)核酸检测结果的准确性,本试验建立PEDV微滴式数字聚合酶链式反应(ddPCR)检测方法;制备PEDV(GHN/HB01株)灭活病毒标准物质,通过实时荧光定量PCR(qPCR)和PCR方法检测外源病原体以评价其纯净性;采用ddPCR方法检测PEDV N基因的绝对定量值以评估该标准物质的均匀性、稳定性并与9家实验室合作定值;进一步采用qPCR方法对该标准物质进行应用评估。结果显示,本试验建立并优化了PEDV ddPCR方法,制备的PEDV(GHN/HB01株)灭活病毒标准物质不存在外源病原体感染;组内和组间无显著性差异(P>0.05),均匀性好;该标准物质于-20℃稳定保存9个月,4℃稳定保存7 d,25℃稳定保存24 h,可反复冻融3次;该标准物质定值结果为(1.64±0.2624)×10^(3)copies/μL;应用评估证实,该标准物质在qPCR检测体系中表现可靠,适用性良好,可以用于qPCR检测。结果表明,本试验研制的PEDV(GHN/HB01株)灭活病毒标准物质具备准确的定值和良好的稳定性,可直接应用于检测试剂盒开发、实验室方法验证与质量控制全过程,是实现PEDV核酸检测标准化的关键物质基础。 展开更多
关键词 猪流行性腹泻病毒(PEDV) N基因 微滴式数字PCR(ddPCR) 标准物质 定值
在线阅读 下载PDF
考虑碳排放的交通流分配与交通系统最优模型及算法研究
5
作者 姚明山 赵磊 朱道立 《管理工程学报》 北大核心 2026年第1期274-286,共13页
二氧化碳和一氧化碳会对人体健康和生态环境产生严重危害,而道路交通是二氧化碳和一氧化碳排放的主要源头之一。因此,考虑车辆碳排放的交通分配问题是可持续发展时代交通科学领域的重要科学问题,主要包括:考虑碳排放的环境交通流分配问... 二氧化碳和一氧化碳会对人体健康和生态环境产生严重危害,而道路交通是二氧化碳和一氧化碳排放的主要源头之一。因此,考虑车辆碳排放的交通分配问题是可持续发展时代交通科学领域的重要科学问题,主要包括:考虑碳排放的环境交通流分配问题(environmental traffic assignment problem,ETAP)和环境交通系统最优问题(environmental system optimization,ESOP)。与传统的交通分配问题(traffic assignment problem,TAP)和交通系统最优问题(system optimization problem,SOP)不同的是,ETAP和ESOP问题属于带交通网络约束的非凸优化问题,求解难度较大。这使得对ETAP和ESOP问题的求解方法设计成为当今交通科学与决策科学界的前沿难题。本文将基于作者提出的带约束的非凸最优化一阶原始/对偶方法理论,分析ETAP和ESOP问题的数学性质,并设计可用于求解ETAP和ESOP问题的算法,证明该算法能够收敛到ETAP问题的均衡点和ESOP问题的最小点。最后,本文在一个小型交通网络和经典的Nguyen和Dupuis交通网络上进行仿真实验,验证本文提出的算法能有效求解ETAP和ESOP问题。此外,通过对小型交通网络的案例分析,本文揭示了ETAP中的一些重要现象:ETAP部分局部极小均衡点存在一个稳定区域,当起始点位于该区域时,算法将迅速收敛到该均衡点;而算法一定不会收敛到ETAP的某个局部极大均衡点,除非起始点选择该均衡点。 展开更多
关键词 环境交通分配问题 环境交通系统最优问题 非凸约束最优化算法
在线阅读 下载PDF
Design of Cellular Manufacturing Systems Considering Dynamic Production Planning and Worker Assignments
6
作者 Tariq Aljuneidi Akif A. Bulgak 《Journal of Mathematics and System Science》 2016年第1期1-15,共15页
This article presents a comprehensive mathematical model for the design and analysis of Dynamic Cellular Manufacturing Systems (DCMS). The proposed DCMS model considers several manufacturing attributes such as multi... This article presents a comprehensive mathematical model for the design and analysis of Dynamic Cellular Manufacturing Systems (DCMS). The proposed DCMS model considers several manufacturing attributes such as multi period production planning, dynamic system reconfiguration, duplicate machines, machine capacity, the available time for workers, worker assignments, and machine procurement. The objective is to minimize total costs; consisting of holding cost, outsourcing cost, inter-cell material handling cost, maintenance and overhead cost, machine relocation cost. While a study of published articles in the area of Cellular Manufacturing Systems (CMS) shows that workforce management issues have not sufficiently been addressed in the literature, the model presented also incorporates CMS workforce management issues such as salaries, hiring and firing costs of workers in addition to the manufacturing attributes. In-depth discussions on the results for two numerical examples are presented to illustrate applications of the proposed model. The model developed aims to raise the envelope by expanding and improving several CMS models previously presented in the literature. 展开更多
关键词 Facilities planning and design Cellular Manufacturing Systems Mixed Integer Programming Production Planning Worker assignments.
在线阅读 下载PDF
中国交通碳排放关联网络的时空动力学与驱动机制
7
作者 张晨 汪秀婷 +2 位作者 杨青 刘星星 陈英杰 《环境科学》 北大核心 2026年第1期23-35,共13页
研究中国省域交通碳排放关联网络的时空依赖特征与格局及其驱动机制,对促进省域间交通碳减排与区域高质量减排协同发展具有重要意义.基于二次指派程序、社会网络分析以及探索性时空数据分析并结合多元回归二次指派程序模型探讨2003~202... 研究中国省域交通碳排放关联网络的时空依赖特征与格局及其驱动机制,对促进省域间交通碳减排与区域高质量减排协同发展具有重要意义.基于二次指派程序、社会网络分析以及探索性时空数据分析并结合多元回归二次指派程序模型探讨2003~2021年中国交通碳排放关联网络的时空动力演化交互特征与驱动机制.结果表明:(1)2003~2021年中国交通碳排放关联网络结构与强度相似度高,连接模式存在“时间惯性”,未来关联模式受历史关联状态影响明显.(2)中国交通碳排放关联网络的空间连接偏好特征明显,空间异质性突出,集聚分布日趋明显,山东、江苏、广东与上海等核心省域主导现象突出.(3)在时空交互维度上交通碳排放锁定效应与跃迁惰性突出,研究期间内省域间协同合作关系高达84.6%,但西南和北部省域间时空竞争关系突出.(4)交通碳排放关联网络的驱动机制呈现出“结构锁定-时空依赖-个体属性多样性”的特点,其中经济差异矩阵与时空交互网络对其正向影响最为显著,产业差异矩阵与运输结构差异矩阵产生同配效应的负向影响最为突出.因此建议各省从区域间协调治理、差异化减碳政策以及交通网络布局这3个方面推动区域交通碳减排目标优化与协同发展. 展开更多
关键词 交通碳排放 时空动态变化 探索性时空数据分析(ESTDA) 多元回归二次指派程序(MRQAP) 驱动机制
原文传递
结合性别信息的多任务语音情感识别
8
作者 姚佳 李冬冬 王喆 《计算机科学》 北大核心 2026年第1期180-186,共7页
现有的语音情感识别方法通常依赖深度学习模型提取声学特征,但大多仅关注通用特征的建模,未能充分挖掘数据中与情感密切相关的先验知识。为此,提出了一种端到端的多任务学习框架,利用自监督预训练模型WavLM提取包含丰富情感信息的语音特... 现有的语音情感识别方法通常依赖深度学习模型提取声学特征,但大多仅关注通用特征的建模,未能充分挖掘数据中与情感密切相关的先验知识。为此,提出了一种端到端的多任务学习框架,利用自监督预训练模型WavLM提取包含丰富情感信息的语音特征,并将性别识别作为辅助任务,以捕捉性别差异对情感识别的潜在影响。针对传统多任务学习框架中固定权重计算损失导致的学习不均衡问题,进一步提出了一种自适应温度系数的动态权重平均方法(Temperature-aware Dynamic Weight Averaging,TA-DWA)。该方法通过动态调整温度系数平衡不同任务的学习速度,并结合任务损失变化率实现更合理的权重分配。实验结果表明,在IEMOCAP和EMODB数据集上,所提方法显著提高了情感识别准确率,验证了性别识别作为辅助任务的有效性以及动态权重策略在多任务学习中的优势。 展开更多
关键词 语音情感识别 多任务学习 动态权重分配 自监督模型
在线阅读 下载PDF
Strategies for Effective Comments on Students’ Written Assignments
9
作者 任永东 《教师》 2014年第17期46-46,共1页
Abstract:Comments on students’assignments are important for English course.The loopholes in teachers’working schemes-comments of their students’written assignments are the clues around which the paper spreads.In th... Abstract:Comments on students’assignments are important for English course.The loopholes in teachers’working schemes-comments of their students’written assignments are the clues around which the paper spreads.In the process of teaching,some English teachers pay so much attention to the contents taught in class but ignore the comments on students’written assignments.Consequently,it is not applicable for students to correct their mistakes in time and they probably make the same mistakes repeatedly. 展开更多
关键词 英语学习 学习方法 阅读知识 阅读材料
在线阅读 下载PDF
Assignments of ~1H and ^(13)C NMR Signals of Mogroside Ⅳa 被引量:3
10
作者 ZHANGJian-ye YANGXiu-wei 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第4期196-200,共5页
Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structur... Aim To investigate the structure of mogroside Ⅳa isolated from traditionalChinese medicine fructus mo-mordicae [fruits of Siraitia grosvenori (Swingle) C. Jeffery] andsummarize the NMR characteristics of the structure. Methods Common extraction, separation andpurification methods were used. Various NMR techniques including ~1H NMR, ^(13)C NMR, DEPT, ~1H-~1HCOSY, HSQC, HMBC, NOESY and molecular model simulated by computer were used to elucidate thestructure. Results ~1H and ^(13)C NMR signals of mogroside Ⅳa were assigned, and spectroscopicbasis was obtained for identification of such type of compounds. Conclusion 1D and 2D NMR techniquesincluding ~1H-~1H COSY, HSQC, HMBC, NOESY spectra are powerful tools for structure analysis. Thestructure determined by NMR methods is identical with energy minimized conformation simulated bycomputer. 展开更多
关键词 fructus momordicae mogroside Ⅳa triterpenoid saponin NMR spectrum ASSIGNMENT
暂未订购
杭州市重要湿地生态状况监测及评估
11
作者 王一丹 李伟成 +5 位作者 钱逸凡 张现武 初映雪 吴旭东 姚可侃 翁远玮 《安徽农业科学》 2026年第1期77-82,共6页
[目的]健全重要湿地的生态监测和预警机制。[方法]利用杭州市重要湿地的健康数据,分析其生态状况,全面评估其健康状况。[结果]杭州市7处重要湿地的生态健康状况评估得分和预警等级为千岛湖金竹牌(0.916,无预警)>萧山湘湖(0.756,黄色)... [目的]健全重要湿地的生态监测和预警机制。[方法]利用杭州市重要湿地的健康数据,分析其生态状况,全面评估其健康状况。[结果]杭州市7处重要湿地的生态健康状况评估得分和预警等级为千岛湖金竹牌(0.916,无预警)>萧山湘湖(0.756,黄色)=富阳阳陂湖(0.756,黄色)=钱塘大湾区(0.756,黄色)>西溪湿地(0.750,黄色)>余杭三白潭(0.711,黄色)>淳安千亩田(0.640,黄色);萧山湘湖、富阳阳陂湖和西溪湿地的生态状况具有同质性,受到入侵物种的威胁,植被原真性下降;钱塘大湾区受到周围企业工厂排污的影响;余杭三白潭受到水体富营养化和入侵物种的影响;淳安千亩田受到本土物种种群扩张和旱化的影响。[结论]采用的指标及其赋值系统简洁且契合了杭州重要湿地的生态状况,为湿地生态系统的保护、合理利用和可持续管理提供基础信息和决策依据。 展开更多
关键词 重要湿地 生态状况 健康状况 预警机制 指标赋值
在线阅读 下载PDF
从入声调归派格局看北京方言的历史演变
12
作者 刘泽民 《苏州工学院学报》 2026年第1期47-70,共24页
本文基于入声调归派格局,探讨北京官话的历史演变及其与官话其他次方言的亲缘关系。入声调归派是官话分区的核心标准,各次方言依此形成了各自的独特格局:北京、冀鲁、胶辽官话属三分型(清入归派规则各异);中原、兰银官话为二分型;江淮... 本文基于入声调归派格局,探讨北京官话的历史演变及其与官话其他次方言的亲缘关系。入声调归派是官话分区的核心标准,各次方言依此形成了各自的独特格局:北京、冀鲁、胶辽官话属三分型(清入归派规则各异);中原、兰银官话为二分型;江淮、西南官话为合流型。通过对近900个方言点大数据的分析,本文验证了各格局的稳定性,其例外多由方言接触或历史层叠导致。文献对比表明,《中原音韵》入声归派与元代北京话高度契合,现代北京话清入复杂归派源于明代以来的方言混合与接触音变。研究发现,燕京官话与冀鲁、胶辽官话共享三分型格局,暗示其共同的历史渊源;中原官话二分型则代表了另一演变路径。方言接触理论解释了清入多向归派的成因。本文为北京话溯源及官话的历史关系研究提供了新视角,并强调了系统性活语言数据在历史语言学研究中的核心地位。 展开更多
关键词 北京官话 入声调归派格局 历史演变 官话内部关系
在线阅读 下载PDF
Computer Assisted Assignments of Rotationally Resolved Molecular Spectra 被引量:1
13
作者 Ling Wu Li-juan Zheng +2 位作者 Xiao-hua Yang Yu-yan Liu Yang-qin Chena 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第1期39-42,共4页
A graphically oriented interactive program for assignments of rotationally resolved molecular spectra has been devised. The program functions by grouping spectral lines in term of the second difference principle. and ... A graphically oriented interactive program for assignments of rotationally resolved molecular spectra has been devised. The program functions by grouping spectral lines in term of the second difference principle. and graphing spectral intensity versus frequency in a bar graph of the selected groups, distinguished by color and/or line-type. This allows for easy detection of regular patterns buried in the observed spectrum. Furthermore, it includes a Loomis-Wood view for assisting in spectral assignments. As an example, the program was applied in assigning the molecular spectrum of the production in the discharge of PCl3 buffered by helium gas, which may belong to several species. The results suggest that the program is highly efficient and quite useful in the assignment and the analysis of molecular spectra, especially those of symmetric top, slightly asymmetric top and linear molecules. The accuracy and efficiency of this program will likely ensure its wide application in the processing of molecular spectra. 展开更多
关键词 ASSIGNMENT Rotationally resolved Molecular spectra Computer assisted
在线阅读 下载PDF
基于异构图表示学习和D3QN-PER的外卖即时配送问题的优化研究
14
作者 张文强 黄永生 《物流技术》 2026年第1期57-67,共11页
随着O2O外卖行业的快速发展,动态订单分配与路径优化已成为提升配送效率的核心挑战。针对外卖即时配送问题中订单动态生成、备餐时间不确定、骑手与订单间的跨类型交互特性,提出一种基于异构图表示学习模块(Heterogeneous Graph Represe... 随着O2O外卖行业的快速发展,动态订单分配与路径优化已成为提升配送效率的核心挑战。针对外卖即时配送问题中订单动态生成、备餐时间不确定、骑手与订单间的跨类型交互特性,提出一种基于异构图表示学习模块(Heterogeneous Graph Representation Learning,HGRL)与带有优先经验回放机制的决斗双深度Q网络(Dueling Double Deep Q Network with Prioritized Experience Replay,D3QNPER)算法相结合的模型。首先,本文将外卖配送系统建模为异构图,通过异构图注意力网络捕捉骑手节点与订单节点的交互关系,构建基于路径的马尔可夫决策过程(Markov Decision Process,MDP),以刻画动态决策场景。对比实验结果表明:D3QN-PER算法对应的平均客户服务水平更高,平均配送距离和配送时间更短,订单延迟率更低,且该算法具有更好的收敛性、训练稳定性和泛化性。 展开更多
关键词 外卖配送 深度学习 强化学习 异构图 马尔可夫决策 订单分配 路径规划
在线阅读 下载PDF
Chemical shift assignments of two oleanane triterpenes from Euonymus hederaceus
15
作者 胡合姣 王奎武 +2 位作者 吴斌 孙翠荣 潘远江 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE EI CAS CSCD 2005年第8期719-721,共3页
1H-NMR and 13C-NMR assignments of 12-oleanene-3,11-dione (compound 1) were completely described for the first time through conventional 1D NMR and 2D shift-correlated NMR experiments using 1H-1HCOSY, HMQC, HMBC techni... 1H-NMR and 13C-NMR assignments of 12-oleanene-3,11-dione (compound 1) were completely described for the first time through conventional 1D NMR and 2D shift-correlated NMR experiments using 1H-1HCOSY, HMQC, HMBC techniques. Based on its NMR data, the assignments of 28-hydroxyolean-12-ene-3,11-dione (compound 2) were partially revised. 展开更多
关键词 Euonymus hederaceus 12-oleanene-3 11-dione 28-hydroxyolean- 12-ene-3 11-dione 1D-NMR 2D-NMR Assignment
暂未订购
Configuration and Spin Assignments of Yrast Band for Doubly Odd Nucleus ^(122)Cs
16
作者 PU Yun-wei WEN Jia-yan +1 位作者 ZHU Shun-quan ZHENG Ren-rong 《Chinese Physics Letters》 SCIE CAS CSCD 1998年第7期480-482,共3页
Energy spectrum of yrast band for ^(122)Cs is studied by using particle-rotor model(PRM)of odd-odd nuclei,in which special attention is paid to the model basis accounting for the effect of the instabilityγvibration p... Energy spectrum of yrast band for ^(122)Cs is studied by using particle-rotor model(PRM)of odd-odd nuclei,in which special attention is paid to the model basis accounting for the effect of the instabilityγvibration perturbation around axial symmetry.In order to check the assignments of this band,two calculation schemes are put into practice.The first one is for previousπh11/2 vg7/2 configuration with bandhead spin I_(0)=(6^(-))which was obtained from cranked shell model(CSM)calculation,and the other one is forπh_(11/2) vh_(11/2) configuration with I_(0)=(9^(+))supported by the systematic analyses of experimental data.A qualitative comparison between the present PRM calculation and that of CSM has also been made.The results indicate that,rather thanπh_(11/2) vg_(7/2) I_(0)=(6^(-)),πh_(11/2) vh_(11/2) with I_(0)=(9^(+))is a more reasonable assignment to the yrast band in ^(122)Cs. 展开更多
关键词 ASSIGNMENT CONFIGURATION
原文传递
Graphs with <i>k</i>-Role Assignments
17
作者 Yana Liu Yongqiang Zhao 《Open Journal of Discrete Mathematics》 2017年第3期177-184,共8页
For a given graph G, a k-role assignment of G is a surjective function ?such that , where N(x) and N(y) are the neighborhoods of x and y, respectively. Furthermore, as we limit the number of different roles in the nei... For a given graph G, a k-role assignment of G is a surjective function ?such that , where N(x) and N(y) are the neighborhoods of x and y, respectively. Furthermore, as we limit the number of different roles in the neighborhood of an individual, we call r a restricted size k-role assignment. When the hausdorff distance between the sets of roles assigned to their neighbors is at most 1, we call r a k-threshold close role assignment. In this paper we study the graphs that have k-role assignments, restricted size k-role assignments and k-threshold close role assignments, respectively. By the end we discuss the maximal and minimal graphs which have k-role assignments. 展开更多
关键词 NEIGHBORHOOD k-Role ASSIGNMENT Restricted Size k-Role ASSIGNMENT k-Threshold Close Role ASSIGNMENT
暂未订购
^(1)H and ^(13)C NMR spectral assignments for low-concentration bile acids in biological samples
18
作者 Hong Lin Junbo He +1 位作者 Weinong Zhang Huiru Tang 《Magnetic Resonance Letters》 2023年第4期277-285,共9页
Bile acids are the main body of enterohepatic circulation in vivo.They have essential functions such as emulsifying fat,bacteriostasis and regulating multiple metabolic pathways as signal molecules.However,the assignm... Bile acids are the main body of enterohepatic circulation in vivo.They have essential functions such as emulsifying fat,bacteriostasis and regulating multiple metabolic pathways as signal molecules.However,the assignments of NMR signals for some lowconcentration bile acids are still needed.This study combined 1D nuclear magnetic resonance(NMR)and 2D NMR techniques including 1He1H correlation spectroscopy(COSY),1He1H total correlation spectroscopy(TOCSY),1H J-resolved spectroscopy(J-Res),1He13C heteronuclear single quantum coherence spectroscopy(HSQC),and 1He13C heteronuclear multiple bond correlation spectroscopy(HMBC)to assign the 1H and 13C signals of six bile acids in aqueous solution at physiological pH(~7.4)and nine bile acids in methanol.These data are of importance to the NMR-based studies on lipid digestion,absorption,and metabolism. 展开更多
关键词 Bile acids ^(1)H NMR ^(2)D NMR Signal assignments
在线阅读 下载PDF
大作业观视角下的生物学单元作业设计与实践 被引量:1
19
作者 张凌霞 张锋 《生物学教学》 北大核心 2025年第4期54-57,共4页
以“遗传信息的传递”单元为例,阐述单元作业设计与实践路径包括:以概念进阶为线索,通过制订素养指向的单元作业目标,实现单元作业的大取向;基于真实性的大情境及多重情境编制,形成课前、课中和课后作业链,实现单元作业的大设计;在完成... 以“遗传信息的传递”单元为例,阐述单元作业设计与实践路径包括:以概念进阶为线索,通过制订素养指向的单元作业目标,实现单元作业的大取向;基于真实性的大情境及多重情境编制,形成课前、课中和课后作业链,实现单元作业的大设计;在完成作业的过程中,通过融入以学习化评估为主导的学本评估,实现单元作业的大评价。旨在学生深刻理解与运用生物学概念性知识,发展科学思维能力与科学探究能力。 展开更多
关键词 大作业观 单元作业 概念进阶 遗传信息 情境
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部