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MICROENVIRONMENTAL EFFECT ON THE INTRAMOLECULAR PHOTOCHEMICAL INTERACTION OF BIS-COUMARINYL COMPOUNDS CONTAINING ALKYL CHAINS
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作者 Gao, H Wang, GC +4 位作者 Liang, LJ He, BL Du, DM Wang, YM Meng, JB 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第8期753-755,共3页
The intramolecular photochedcal interaction of a series of bis-coumarinyl compounds with various alkyl chain lengths (An) has been studied in/without the presence of β-cyclodextrin (β-CD) by fluorescence spectroscop... The intramolecular photochedcal interaction of a series of bis-coumarinyl compounds with various alkyl chain lengths (An) has been studied in/without the presence of β-cyclodextrin (β-CD) by fluorescence spectroscopy. The results show that both photedimerization andexcimer formation can occur in the respective favourable microenvironments. 展开更多
关键词 biS COUMARINYL OF interaction CHAINS ALKYL
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THE SYNTHESIS OF 4,5-BIS(4'-BROMOBENZYLTHIODITHIOLE-2-THIONE WITH ONE DIMENSIONAL INTERMOLECULAR INTERACTIONS
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作者 Fang QI(Institute of Crystal Materials, Shandong University, Jinan, 250100) 《Chinese Chemical Letters》 SCIE CAS CSCD 1996年第2期103-104,共2页
The title compound BBBT-Dry (C17H12Br2S5, Mr=536.42) has been synthesized and its structure feature has been described. BBBT-DTT is characterized by one dimensional chains formed by S…S (head to head) and Br…Br (tai... The title compound BBBT-Dry (C17H12Br2S5, Mr=536.42) has been synthesized and its structure feature has been described. BBBT-DTT is characterized by one dimensional chains formed by S…S (head to head) and Br…Br (tail to tail) intermolecular interactions. 展开更多
关键词 biS THIONE WITH INTERMOLECULAR interactionS OF SYNTHESIS DITHIOLE DIMENSIONAL BROMOBENZYLTHIO
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Weak Interactions and 2D Layer Structure of a New Ion-pair Complex Bis(1-benzyl-4-methylquinolinium)-bis(maleonitriledithiolato)nickel(Ⅱ)
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作者 周家容 倪春林 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2007年第11期1263-1266,共4页
A new ion-pair complex, [BzMeQ1]2[Ni(nmt)2]1([BzMeQ1]^+ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate) has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction ... A new ion-pair complex, [BzMeQ1]2[Ni(nmt)2]1([BzMeQ1]^+ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate) has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction methods. Complex 1 is of triclinic, space group PI, with a = 9.079(2), b = 10.154(2), c = 11.243(2)A, α= 81.58(1), β= 69.63(1), γ = 68.02(1)°, V= 940.1(3)A3, Dc = 1.427 g/cm^3, Z = 1, F(000) = 418 and R = 0.0442. A 2D layer structure is formed via the cation-cation π…π and C-H…π interactions observed in the solid state of the complex. 展开更多
关键词 1-benzyl-4-methylquinolinium bis (maleonitriledithiolate)nickclatc(Ⅱ) complex weak interactions 2D layer structure
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Interaction energy of interface dislocation loops in piezoelectric bi-crystals
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作者 Jianghong Yuan Yin Huang +1 位作者 Weiqiu Chen Ernian Pan 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2017年第2期76-80,共5页
Interface dislocations may dramatically change the electric properties, such as polarization, of the piezoelectric crystals. In this paper, we study the linear interactions of two interface dislocation loops with arbi... Interface dislocations may dramatically change the electric properties, such as polarization, of the piezoelectric crystals. In this paper, we study the linear interactions of two interface dislocation loops with arbitrary shape in generally anisotropic piezoelectric bi-crystals. A simple formula for calculating the interaction energy of the interface dislocation loops is derived and given by a double line integral along two closed dislocation curves. Particularly, interactions between two straight segments of the interface dislocations are solved analytically, which can be applied to approximate any curved loop so that an analytical solution can be also achieved. Numerical results show the influence of the bi-crystal interface as well as the material orientation on the interaction of interface dislocation loops. 展开更多
关键词 Interface dislocation Piezoelectric bi-crystals Anisotropic elasticity interaction energy
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用酵母双杂交系统研究载脂蛋白AI(apoAI)和清道夫受体BI(SR-BI)间的相互作用 被引量:3
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作者 信学雷 陈志慧 +3 位作者 李维琪 刘云英 麦迪娜 张云峰 《中国生物工程杂志》 CAS CSCD 北大核心 2005年第5期80-84,共5页
目的:利用酵母双杂交系统验证在胆固醇逆转运过程中起关键作用的大鼠载脂蛋白AI(apoAI)和清道夫受体BI- (SR -BI)间存在着相互作用,为初步筛选具有降脂活性组分提供1对新的靶点。方法:首先分别克隆了Wistar大鼠的apoAI和SR -BI基因的cDN... 目的:利用酵母双杂交系统验证在胆固醇逆转运过程中起关键作用的大鼠载脂蛋白AI(apoAI)和清道夫受体BI- (SR -BI)间存在着相互作用,为初步筛选具有降脂活性组分提供1对新的靶点。方法:首先分别克隆了Wistar大鼠的apoAI和SR -BI基因的cDNA ,并构建了酵母表达载体,利用共转化技术观察到apoAI和SR -BI间存在着相互作用,并在酵母交配实验中证实了这个结果。结果:经共转化后的实验组与阳性对照组可在SD/ -Leu/- Trp/- His/- Ade/X -α- Gal平板上生长且菌斑呈蓝色,经测定α、β半乳糖苷酶活力可知酶活分别为8~1 2U和1 0~40U。酵母交配后的二倍体实验组、阳性对照组可在SD/- Leu/- Trp/ -His/- Ade/X -α- Gal平板上生长且菌斑呈蓝色。结论:apoAI和SR BI间的确存在相互作用。 展开更多
关键词 酵母双杂交系统 载脂蛋白AI 清道夫受体bi 相互作用 胆固醇 逆转运 降血脂药物 基因表达
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Bi在Fe液中的溶解平衡及Ni,Mn的影响 被引量:2
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作者 徐建伦 宋波 +2 位作者 陈继开 韩其勇 蒋国昌 《金属学报》 SCIE EI CAS CSCD 北大核心 1993年第1期B017-B020,共4页
用气液平衡法,在密封Mo反应室中研究了1873K下Fe液中Bi蒸气溶解平衡及第三组元Ni,Mn对其的影响,测定了1873K下Bi在Fe液中的溶解量(wt—%)为0.16。Ni,Mn增加Bi的溶解量,其活度相互作用系数为e_(Bi)^(Ni)=-0.20,e_(Bi)^(Mn)=-0.19。
关键词 溶解平衡 相互作用系数 铁液
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基于黑板模型的心电图解释系统BBIS-ECG设计 被引量:3
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作者 杨毓英 史习智 蔡悦斌 《北京生物医学工程》 北大核心 1996年第4期193-198,共6页
作者提出一种基于黑板模型的心电信号解释系统的设计方案,该系统模拟心电专家诊断的思维过程,通过样本学习自动获取模糊规则,以启发性知识控制诊断流程,并通过对模糊量隶属度函数和模糊规则可信度因子的计算,以双向非精确推理进行... 作者提出一种基于黑板模型的心电信号解释系统的设计方案,该系统模拟心电专家诊断的思维过程,通过样本学习自动获取模糊规则,以启发性知识控制诊断流程,并通过对模糊量隶属度函数和模糊规则可信度因子的计算,以双向非精确推理进行诊断。同时,将计算模型纳入知识库,应用信号处理的基本原理在信号处理与信号解释之间也建立了双向作用,实现了真正意义上的定性推理与定量计算的结合。并利用同一通道信号的上下文信息及不同通道间的相关信息协助诊断,更有效地利用了数据信息。 展开更多
关键词 符号化 知识获取 黑板模型 信号解释 心电图
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基于Bi-LSTM的人机语音交互 被引量:7
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作者 张锋 陶浩兵 +3 位作者 慕京生 刘东阳 辜丽川 焦俊 《传感器与微系统》 CSCD 北大核心 2022年第4期104-107,116,共5页
人的语音具有一定的上下文相关性,传统语音识别模型对历史信息记忆能力不足,无法充分学习语音序列的相关性。根据人对机器人控制的语音特点,设计了一种基于双向长短时记忆(Bi-LSTM)网络的控制机器人的语音识别模型,并在自己制作的语音... 人的语音具有一定的上下文相关性,传统语音识别模型对历史信息记忆能力不足,无法充分学习语音序列的相关性。根据人对机器人控制的语音特点,设计了一种基于双向长短时记忆(Bi-LSTM)网络的控制机器人的语音识别模型,并在自己制作的语音库中训练,优化了模型参数。实验结果表明:远端控制命令通过语音识别模型转化为控制命令,传送到机器人的人际交互系统,较好地完成了人对机器人发出的运动控制、状态反馈和环境监测的任务,控制机器人命令语音识别的准确率达到80%以上。 展开更多
关键词 双向长短时记忆 语音识别 人机交互 信息采集
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THE BI DIRECTIONAL REGULATION OF FILAMIN ON THE ATPase ACTIVITY OF SMOOTH MUSCLE MYOSIN 被引量:9
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作者 林原 孙惠君 +3 位作者 戴淑芳 唐泽耀 贺欣 陈华 《Chinese Medical Sciences Journal》 CAS CSCD 2000年第3期162-164,共3页
The aim of this study is to investigate the functional relationship between filamin, a known actin binding protein, and myosin and the effects of filamin on the interaction between myosin and actin. Methods.Ultra cent... The aim of this study is to investigate the functional relationship between filamin, a known actin binding protein, and myosin and the effects of filamin on the interaction between myosin and actin. Methods.Ultra centrifugation method was used to investigate the binding of filamin to both phosphorylated and unphosphorylated myosins. Mg ATPase activities of both phosphorylated and unphosphorylated myosins in the presence and absence of actin were measured to observe the effects resulted from filamin actin and filamin myosin interactions. Results. It was found that filamin is also a myosin binding protein. Filamin inhibited the actin activated Mg ATPase activity of phosphorylated myosin and stimulated Mg ATPase of phosphorylated myosin in the absence of actin; in addition, filamin stimulated Mg ATPase activity of unphosphorylated myosin in both the presence or absence of actin. Conclusion. The results suggest that the effects of filamin on the myosin Mg ATPase activities are bi directional, i.e., stimulatory via binding to myosin and inhibitory via binding to actin. 展开更多
关键词 bi directional regulation myosin binding myosin actin interaction
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Bi^(3+)敏化Sr_(1.8)Eu_(0.8-x)V_(1.2)P_(0.8)O_8的发光性质(英文)
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作者 李瀚博 郑赣鸿 +2 位作者 李勇强 戴振翔 聂笑笑 《安徽大学学报(自然科学版)》 CAS 北大核心 2015年第2期43-49,共7页
采用固相法制备Sr1.8Eu0.8-xBixV1.2P0.8O8(0≤x≤0.7)系列粉末样品.研究样品中的Bi和Eu的相互作用,并讨论相关机理.用X射线衍射和荧光分光光度计对样品的结构和光学性质进行研究,结果表明:x=0.30时,样品的发光强度最强.
关键词 发光材料 敏化剂 bi-Eu相互作用
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Synthesis,Crystal Structure and Characterization of a New Coordination Polymer from the Self-assembly of CoCl_2 Salt and Flexible Ligand 1,3-Bis(4-pyridyl)propane 被引量:3
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作者 范乐庆 吴季怀 +1 位作者 林建明 黄昀昉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2010年第10期1489-1494,共6页
A new 1D coordination polymer [Co(bpp)3Cl2(H2O)2]n 1 (bpp = 1,3-bis(4-pyridyl)-propane) was synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction. The crystal bel... A new 1D coordination polymer [Co(bpp)3Cl2(H2O)2]n 1 (bpp = 1,3-bis(4-pyridyl)-propane) was synthesized and characterized by elemental analysis,IR spectrum and single-crystal X-ray diffraction. The crystal belongs to the orthorhombic system,space group Ibca with a = 16.569(9),b = 17.240(10),c = 27.087(16) ,V = 7738(8) 3,Z = 8,Dc = 1.306 g/cm3,Mr = 760.65,λ(MoKa) = 0.71073 ,μ = 0.623 mm1,F(000) = 3192,the final R = 0.0678 and wR = 0.2011. The Co(II) atom is coordinated in a slightly distorted octahedral CoN4Cl2 geometry by two Cl atoms in the axial positions,four N atoms from the two bridging bpp ligands and two pendant bpp ligands. The CoN4Cl2 octahedra are connected by the bridging bpp ligands to form a 1D neutral coordination polymer chain. The chains are linked by face-to-face π-π interactions between adjacent pendant bpp ligands to give rise to a 3D supramolecular architecture. The photoluminescent investigation indicates that the emission of 1 is attributed to ligand-centered emission. The variable-temperature magnetic susceptibility measurement shows weak antiferromagnetic behavior in the coπmplex. 展开更多
关键词 Co(II) 1 3-bis(4-pyridyl)propane crystal structure π-π interactions CHARACTERIZATION
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Synthesis and Crystal Structure of 1,4-Bis-(benztriazol-1-ylmethyl)-2,3,5,6-tetramethylbenzene
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作者 CAI Yue-Peng HE Guang-Ping +3 位作者 CAI Yi ZHANG Chi SU Cheng-Yong KANG Bei-Sheng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第3期279-282,共4页
The title compound 1,4-bis(benztriazol-1-ylmethyl)-2,4,5,6-trimethylbenzene crys- tallizes in the monoclinic system, space group Pbca with a = 9.842(5), b = 9.455(5), c = 22.165(12) ?, V = 2062.6(18) ?3, Dc = 1.277 ... The title compound 1,4-bis(benztriazol-1-ylmethyl)-2,4,5,6-trimethylbenzene crys- tallizes in the monoclinic system, space group Pbca with a = 9.842(5), b = 9.455(5), c = 22.165(12) ?, V = 2062.6(18) ?3, Dc = 1.277 g/cm3, Z = 4, C24H24N6, Mr = 396.49, μ(MoKa) = 0.079 mm-1 and F(000) = 840. The structure was refined to R = 0.0662 and wR = 0.1891 for 1163 observed reflections (I > 2σ(I)). The title molecule has trans-conformation about the central phenyl ring. The zigzag-like molecules are connected by face-to-face π…π stacking to form an infinite 2D layer. 展开更多
关键词 bis(benztriazol-1-ylmethyl)-2 4 5 6-trimethylbenzene synthesis crystal structure face-to-faceπ…πinteraction 2D layer
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Comparison of base-isolated liquid storage tank models under bi-directional earthquakes
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作者 Sandip Kumar Saha Vasant A. Matsagar Arvind K. Jain 《Natural Science》 2013年第8期27-37,共11页
Seismic response of ground supported baseisolated liquid storage tanks are evaluated under bi-directional earthquakes. The base-isolated liquid storage tanks are modeled using mechanical analogs with two and three lum... Seismic response of ground supported baseisolated liquid storage tanks are evaluated under bi-directional earthquakes. The base-isolated liquid storage tanks are modeled using mechanical analogs with two and three lumped masses (Model 1 and Model 2). Two types of isolation systems, such as sliding system and elastomeric system, are considered for the present study. The isolation systems are modeled using Wen’s equation for hysteretic isolation systems. Response of base-isolated liquid storage tanks, evaluated through two different modeling approaches, is compared. Both the models predict similar sloshing displacement. The effect of interaction between the mutually perpendicular seismic responses of the isolator is investigated for both the models. It is observed that interaction affects the peak seismic response of the base-isolated liquid storage tanks significantly, under the bi-directional earthquake components. 展开更多
关键词 BASE ISOLATION bi-Directional EARTHQUAKE interaction LIQUID SLOSHING TANK
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Fluorescent Switch Behavior of 1, 2-Bis(4-pyridyl) Ethylene Controlled by pH in Aqueous Solution
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作者 ZOU Wen-sheng SHEN Qian-jin +1 位作者 WANG Yu JIN Wei-jun 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2008年第6期712-716,共5页
With the decrease of pH value from 8.45 to -1.0, the UV-Vis absorption and fluorescent spectra of 1,2-bis(4-pyridyl) ethylene(BPE) took on the same changing trend at four different successive pH stages: 8.45--7.2... With the decrease of pH value from 8.45 to -1.0, the UV-Vis absorption and fluorescent spectra of 1,2-bis(4-pyridyl) ethylene(BPE) took on the same changing trend at four different successive pH stages: 8.45--7.20, 7.20--5.62, 5.62--2.60, and 2.60--1.0, namely, no change, decrease, increase, and decrease again. Among these, in a range of 7.20--5.62, the fluorescence wavelength blueshifted from 418 to 359 nm, but the UV-Vis absorption wavelength, in contrast, redshifted from 285 to 298 nm. The fluorescence intensity of BPE had a drop even to quench upon a decline in the pH value from 2.60 to -1.0 probably owing to its cation-re interaction to reduce the π electron cloud density of BPE. Two dissociation constants, pKa1(4.30±0.01) and PKa2(5.65±0.04), were obtained based on fluorescence data. The changes of fluorescence spectra indicate that BPE has "oft-on-off" switch behavior. The fluorescent spectra of BPE were nearly independent on the presence of α- and β-cyclodextrins. 展开更多
关键词 1 2-bis(4-pyridyl) ethylene Fluorescent switch pH fluorescence probe Cation-π interaction
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基于BERT-Bi-IAN的方面级情感分析模型
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作者 何旭 杨柳 黄宇 《河南工程学院学报(自然科学版)》 2023年第1期65-70,共6页
为进一步提高情感识别的准确率,提出了一种基于BERT预训练模型的交互式情感分析模型——BERT-Bi-IAN模型。首先利用BERT预训练模型分别动态表示评价对象及其上下文,然后通过Bi-LSTM网络提取二者的语义信息,随后输入交互式注意力模块,得... 为进一步提高情感识别的准确率,提出了一种基于BERT预训练模型的交互式情感分析模型——BERT-Bi-IAN模型。首先利用BERT预训练模型分别动态表示评价对象及其上下文,然后通过Bi-LSTM网络提取二者的语义信息,随后输入交互式注意力模块,得到二者的交互关系与提取到的语义信息重组评价对象及其上下文的最终表示。模型在中英文数据集中的实验表现证明了与现有经典模型相比,其准确率和F1值有所提升,表明该模型有较大的适用领域。 展开更多
关键词 方面级情感分析 深度学习 交互式注意力机制 BERT预训练模型 BERT-bi-IAN模型
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Two Cobalt(II) Complexes Derived from the Hydrolysis Product of Di-Schiff Base Ligand N,N'-Bis-(1-benzimidazo-2-yl-ethylidene)-ethane-1,2-diamine:Preparation,Characterization and Crystal Structure of the 6-Coordinate Species [CoL_2]X·H_2O (X = ClO_4^-, N 被引量:1
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作者 夏昌坤 吴小园 +2 位作者 吴鼎铭 蒋晓瑜 卢灿忠 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2008年第7期805-811,共7页
The reactions of Co(C1O4)2·6H2O and Co(NO3)2.6H2O with the di-Schiff base ligand N,N'-bis-(1-benzimidazo-2-yl-ethylidene)-ethane-1,2-diamine (LA) in ethanol have been investigated. The reactions of LA wi... The reactions of Co(C1O4)2·6H2O and Co(NO3)2.6H2O with the di-Schiff base ligand N,N'-bis-(1-benzimidazo-2-yl-ethylidene)-ethane-1,2-diamine (LA) in ethanol have been investigated. The reactions of LA with excess amount of cobalt salts yield the six-coordinate complexes [CoL2](ClO4)E·H2O 1 and [CoL2](NO3)E·H2O 2 as isolatable products (L= N-(1- benzimidazo-2-yl-ethylidene)-ethane-1,2-diamine), where L is a tri-dentate mono-Schiff base ligand, resulting from the hydrolysis of the precursor di-Schiff base LA. Both complexes were characterized by X-ray crystallography. Crystal data for complex 1: monoclinic, space group P21/c, a = 11.9214(10), b = 23.5828(17), c = 14.0387(12)A, β = 135.219(4)°, C22H30Cl2CoN8O9, Mr = 680.37, V = 2780.1(4) A^3 ,Z = 4, Dc = 1.625 g/cm^3,μ(MoKa) = 0.876 mm^-1, F(000) = 1404, the final R = 0.0725 and wR = 0.1530 for 5726 observed reflections (I 〉 2σ(I)). Crystal data for complex 2: monoclinic, space group P21/c, a = 18.2162(16), b = 10.0610(6), c = 18.593(2)A, β = 130.099(3)°, C22H30CoN10O7, Mr = 605.49, V = 2606.5(4) A3 Z = 4, Dc = 1.543 g/cm^3,μ(MoKa) = 0.722 mm^-1, F(000) = 1260, the final R = 0.0619 and wR = 0.1429 for 5194 observed reflections (I 〉 2σ(I)). X-ray diffraction analysis reveals that each cobalt atom in the two complexes is chelated by six nitrogen atoms from two tridentate iigands L, exhibiting a slightly distorted octahedral coordination sphere. In both complexes, the strong hydrogen-bonding interactions between the lattice waters and N-H groups of the ligands result in 1D chains which are further connected by ClO4^- (or NO3^-) groups to form a 3D framework. In complex 2, the strong π-π interactions increase the stability of the structure. 展开更多
关键词 2-acetylbenzimidazole di-Schiff base ligand crystal structure hydrolysis hydrogen-bonding interactions coordination complex N N -bis-(1-benzimidazo-2-yl-ethylidene)-ethane- 1 2-diamine N-(1-benzimidazo-2-yl-ethylidene)-ethane- 1 2-diamine
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跨模态语义时空动态交互情感分析研究
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作者 屈立成 郤丽媛 +2 位作者 刘紫君 魏思 董哲为 《计算机工程与应用》 CSCD 北大核心 2024年第1期165-173,共9页
针对传统情感分析中存在的模态间交互性差、时空特征融合度低的问题,建立了一种跨模态的语义时空动态交互网络。通过引入双向长短期记忆网络挖掘各模态的时间序列特征,加入自注意力机制强化模态内特征的权重赋值,将自动筛选出的特征矩... 针对传统情感分析中存在的模态间交互性差、时空特征融合度低的问题,建立了一种跨模态的语义时空动态交互网络。通过引入双向长短期记忆网络挖掘各模态的时间序列特征,加入自注意力机制强化模态内特征的权重赋值,将自动筛选出的特征矩阵送入图卷积神经网络进行语义交互。然后以时间戳为基础进行特征聚合,计算聚合层的相关系数,获得融合后的联合特征,实现跨模态空间交互,最终完成情感极性的分类与预测。使用公开数据集对所提出的模型进行评估验证,实验结果表明,多模态时间序列提取和跨模态语义空间交互机制可以实现模态内和模态间特征的全动态融合,有效地提升了情感分类的准确率和F1值,在CMU-MOSEI数据集上分别提高了1.7%~13.5%和2.1%~14.0%,表现出良好的健壮性和先进性。 展开更多
关键词 跨模态情感分析 语义交互 时空交互 双向长短期记忆网络 图卷积网络
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用于问题生成的知识增强双图交互网络 被引量:1
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作者 李亚峰 叶东毅 陈羽中 《小型微型计算机系统》 CSCD 北大核心 2024年第5期1032-1038,共7页
问题生成是一项具有挑战性的自然语言处理任务,旨在生成具有给定答案和上下文的问题,近年来受到了广泛关注.最近,由于神经网络的发展,问题生成任务取得了较大的进展.然而,现有模型仍然存在未有效利用外部知识以及在利用图神经网络捕获... 问题生成是一项具有挑战性的自然语言处理任务,旨在生成具有给定答案和上下文的问题,近年来受到了广泛关注.最近,由于神经网络的发展,问题生成任务取得了较大的进展.然而,现有模型仍然存在未有效利用外部知识以及在利用图神经网络捕获隐藏结构信息未捕获语法信息等问题.针对上述问题本文提出知识增强双图交互网络KE-BGINN(Knowledge-Enhanced Bi-Graph Interaction Neural Network).首先为了有效利用外部知识信息,KE-BGINN通过知识图谱本身的图结构信息构造知识增强图,并利用图卷积网络对文本以及答案上下文语义信息进行扩充.其次,KE-BGINN引入一种双图交互机制,利用两个图卷积网络学习上下文的隐藏结构信息以及语法信息,在图间信息融合时,构造一个虚拟图来充分融合不同图之间的异构信息.最后,KE-BGINN利用指针网络解码机制来解决问题生成时罕见和未知词的问题.在SQuAD数据集上的实验结果证明,与对比模型相比较,KE-BGINN模型的综合性能更加优异. 展开更多
关键词 问题生成 知识图谱 图卷积网络 双图交互 虚拟图
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气流作用下气道组织变形的流固耦合研究
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作者 秦源 陈茜 +2 位作者 魏东 任晓勇 徐光魁 《力学学报》 EI CAS CSCD 北大核心 2024年第2期472-481,共10页
悬雍垂腭咽成形术(UPPP)是一种治疗阻塞性睡眠呼吸暂停(OSA)的常规外科手术,然而由于手术作用机制仍不清楚,手术成功率较低.现有的研究大多忽略了患者上气道的具体形态以及呼吸作用下气道软组织的弹性变形,不足以有效指导手术治疗.文章... 悬雍垂腭咽成形术(UPPP)是一种治疗阻塞性睡眠呼吸暂停(OSA)的常规外科手术,然而由于手术作用机制仍不清楚,手术成功率较低.现有的研究大多忽略了患者上气道的具体形态以及呼吸作用下气道软组织的弹性变形,不足以有效指导手术治疗.文章基于OSA患者在术前、术后的CT扫描图像,构建了精确的三维上气道模型,通过双向流固耦合(FSI)计算,模拟研究了呼吸作用下上气道软组织的弹性变形和气道内气流流动情况.比较手术成功案例和失败案例中OSA患者上气道的流速、压力分布及气道弹性变形情况,从气道流体流动状态和气道软组织变形的角度解释了OSA的发生原因与手术作用机制.结果表明,最小横截面积尺寸并不是UPPP手术成功与否的决定性因素,成功的手术应当是减轻气道壁负压力程度、降低气道进出口之间的压降.此外,使用双向FSI方法,文章进一步构建了简化的人体二维软腭模型,探究了软腭弹性模量对吸气过程的影响,发现当软腭的弹性模量在0.5~1.5 MPa的范围内时,刚度更小的软腭会改善流场的流动情况,但也更易发生变形塌陷.文章所发展的流固模型为个性化预测手术效果提供了研究工具. 展开更多
关键词 上气道 阻塞性睡眠呼吸暂停 双向流固耦合 压降 数值模拟
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pH值对双(2-甲基-3-呋喃基)二硫醚与α-淀粉酶结合的影响及相互作用机制研究
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作者 奚宇 余美宏 +3 位作者 赵劲灵 曹瑞 程洁仪 李健 《食品与发酵工业》 CAS CSCD 北大核心 2024年第19期171-179,共9页
双(2-甲基-3-呋喃基)二硫醚[bis(2-methyl-3-furyl)disulfide,BMFDS]是肉类的一种关键香气化合物,它与口腔中的α-淀粉酶相互作用,影响人体对香气的感知。该研究采用气相色谱-质谱、紫外吸收光谱、荧光光谱、zeta-电位检测、蛋白质表面... 双(2-甲基-3-呋喃基)二硫醚[bis(2-methyl-3-furyl)disulfide,BMFDS]是肉类的一种关键香气化合物,它与口腔中的α-淀粉酶相互作用,影响人体对香气的感知。该研究采用气相色谱-质谱、紫外吸收光谱、荧光光谱、zeta-电位检测、蛋白质表面疏水性、分子对接分析等方法研究BMFDS与α-淀粉酶之间的相互作用机制以及pH值对其相互作用的影响。结果表明,BMFDS与α-淀粉酶之间自发的相互作用形成了基态复合物,对α-淀粉酶的荧光产生了静态猝灭。不同pH条件下其相互作用强度顺序为pH 7.0>pH 8.5>pH 5.0,但都以疏水相互作用为主。pH会影响BMFDS与α-淀粉酶之间的相互作用强度,但并不会改变二者间的相互作用力和反应类型。总之,BMFDS和α-淀粉酶之间存在非共价相互作用,使α-淀粉酶结构松散,且在3种pH条件下的作用强度有差异。该研究可为后续肉类风味调控提供理论依据。 展开更多
关键词 双(2-甲基-3-呋喃基)二硫醚 Α-淀粉酶 相互作用机制 pH 疏水相互作用
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