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基于多目标优化算法NSGA-Ⅱ的软件多样化组合方法 被引量:1
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作者 谢根琳 程国振 +1 位作者 梁浩 王庆丰 《计算机科学》 CSCD 北大核心 2024年第6期85-94,共10页
软件多样化因能有效提升系统弹性、增加恶意二进制分析的成本而被广泛应用于软件开发等场景中。而如何对现有软件多样化技术进行组合部署,以在获得更高安全增益的同时保持较低的性能开销,是当前软件多样化研究的核心问题之一。针对现有... 软件多样化因能有效提升系统弹性、增加恶意二进制分析的成本而被广泛应用于软件开发等场景中。而如何对现有软件多样化技术进行组合部署,以在获得更高安全增益的同时保持较低的性能开销,是当前软件多样化研究的核心问题之一。针对现有软件多样化组合方法中搜索算法效率低、搜索空间小、安全性评估指标不全面、难以综合考量软件多样化对各类攻击的影响等问题,提出了一种基于多目标优化算法的软件多样化组合方法,将软件多样化组合问题构建为综合考量TLSH相似度、gadget质量分数和CPU时钟周期数指标的多目标优化模型,并设计了包括染色体编码、自适应交叉和变异算子,以及针对组合方案的有效性验证算法等在内的NSGA-Ⅱ求解算法。最后,在GNU核心工具组数据集上进行实验,结果表明,该组合方法可有效生成高安全增益、低性能开销的软件多样化组合方案。 展开更多
关键词 软件多样化 多目标优化 NSGA-算法 多样化技术组合 量化评估
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Solubility study of hydrogen in direct coal liquefaction solvent based on quantitative structure–property relationships model
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作者 Xiao-Bin Zhang A.Rajendran +1 位作者 Xing-Bao Wang Wen-Ying Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第12期250-258,共9页
Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature an... Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature and pre-hydrogenation of the DCLS are critical steps.Therefore,studying the dissolution of hydrogen in DCLS under liquefaction conditions gains importance.However,it is difficult to precisely determine hydrogen solubility only by experiments,especially under the actual DCL conditions.To address this issue,we developed a prediction model of hydrogen solubility in a single solvent based on the machine-learning quantitative structure–property relationship(ML-QSPR)methods.The results showed that the squared correlation coefficient R^(2)=0.92 and root mean square error RMSE=0.095,indicating the model’s good statistical performance.The external validation of the model also reveals excellent accuracy and predictive ability.Molecular polarization(a)is the main factor affecting the dissolution of hydrogen in DCLS.The hydrogen solubility in acyclic alkanes increases with increasing carbon number.Whereas in polycyclic aromatics,it decreases with increasing ring number,and in hydrogenated aromatics,it increases with hydrogenation degree.This work provides a new reference for the selection and proportioning of DCLS,i.e.,a solvent with higher hydrogen solubility can be added to provide active hydrogen for the reaction and thus reduce the hydrogen pressure.Besides,it brings important insight into the theoretical significance and practical value of the DCL. 展开更多
关键词 Hydrogen solubility Liquefied solvents Predictive model Density generalized function theory quantitative structure-property RELATIONSHIP
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基于NSGA-Ⅱ算法的自动驾驶停车泊位优化模型
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作者 于红媚 叶晓飞 +3 位作者 汪义路 陈峻 闫星辰 王涛 《宁波大学学报(理工版)》 CAS 2024年第3期57-69,共13页
完全自动驾驶车辆将具有自动泊车功能,自主泊车技术可实现多排布局的高密度、集约化停车布局,将彻底改变双排多通道的传统停车布局方式.然而,在释放被阻塞车辆时不可避免产生额外的移动和拥堵.为了明晰多排布局产生排队阻塞和额外移动... 完全自动驾驶车辆将具有自动泊车功能,自主泊车技术可实现多排布局的高密度、集约化停车布局,将彻底改变双排多通道的传统停车布局方式.然而,在释放被阻塞车辆时不可避免产生额外的移动和拥堵.为了明晰多排布局产生排队阻塞和额外移动次数与空间利用率提升的悖反规律,综合考虑停车场的几何属性、移动策略、需求特征等设计要素,通过车辆协同让道规则释放阻塞车辆,以泊位数量最大和移动次数最少为双重目标,构建了自动驾驶条件下多排布局方式停车泊位优化模型,设计了带精英策略的非支配排序遗传算法(NSGA-Ⅱ)进行求解,通过数值实验提出了停车设施的最佳区域和布局,同时还进行了不同移动策略的敏感性分析.结果表明,在不降低停车位利用率的前提下,基于就近原则的移动策略大大减少了预期移动次数. 展开更多
关键词 交通工程 泊位优化 NSGA- 自动驾驶车辆 排队论 停车
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Quantitative feedback theory and zero phase error tracking control combined robust control for radar truck leveling simulator 被引量:1
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作者 凌轩 李晓辉 +1 位作者 朱玉泉 冯天麟 《Journal of Shanghai University(English Edition)》 2009年第5期384-390,共7页
Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this ... Radar leveling system is the key equipment for improving the radar mobility and survival capability. A combined quantitative feedback theory (QFT) controller is designed for the radar truck leveling simulator in this paper, which suffers from strong nonlinearities and system parameter uncertainties. QFT can reduce the plant uncertainties and stabilize the system, but it fails to obtain high-precision tracking. This drawback can be solved by a robust QFT control scheme based on zero phase error tracking control (ZPETC) compensation. The combined controller not only possesses high robustness, but greatly improves the system performance. To verify the effiectiveness and the potential of the proposed controller, a series of experiments have been carried out. Experimental results have demonstrated its robustness against a large range of parameters variation and high tracking precision performance, as well as its capability of restraining the load coupling among channels. The combined QFT controller can drive the radar truck leveling platform accurately, quickly and stably. 展开更多
关键词 radar truck leveling simulator quantitative feedback theory (QFT) parameter uncertainties zero phase error tracking control (ZPETC) high robustness
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HRM and Quantitatives: Decision Tree and Vector Analysis in HRM Theory 被引量:2
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作者 Gurhan Uysal 《Chinese Business Review》 2014年第6期382-387,共6页
Research topic of this paper is to discuss theory of Human Resources Management (HRM) and to discuss using of quantitative methods in HRM. Firstly, five variables establish HRM theory. They are HRM practices, positi... Research topic of this paper is to discuss theory of Human Resources Management (HRM) and to discuss using of quantitative methods in HRM. Firstly, five variables establish HRM theory. They are HRM practices, positive organizational behaviors, individual performance, performance of business departments, and firm performance. Transactions among those variables enable Human Resources (HR) practitioners to apply HRM theory in their organizations. Secondly, this paper discusses use of quantitative methods in HRM. They are vector analysis and decision tree analysis. Those analyses enable HR practitioners to make effective HR decisions. Decision tree sets HR alternatives to efficiently implement HRM practices in organizations. Research question is how HR practitioners apply quantitative methods in department of HRM in firms. Finally this research comes out a conclusion that quantitative methods may be used in HRM. 展开更多
关键词 Human Resources Management (HRM) theory VECTORS matrice decision tree quantitative method
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Rheological Behavior for Polymer Melts and Concentrated Solutions——Part Ⅶ: A Quantitative Verification for the Molecular Theory of Non-linear Viscoelasticity with Entanglement Constraints in Polymer Melts 被引量:2
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作者 Mingshi SONG, Chen ZHANG and Guixian HU Research Institute of Polymeric Materials, Beijing University of Chemical Technology, Beijing 100029, China E-mail: wangzhchen@sina.com 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第3期375-382,共8页
Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) ... Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <(<upsilon>)over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts. 展开更多
关键词 Rheological Behavior for Polymer Melts and Concentrated Solutions A quantitative Verification for the Molecular theory of Non-linear Viscoelasticity with Entanglement Constraints in Polymer Melts PART
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IMPROVED QUANTITATIVE FEEDBACK THEORY TECHNIQUE AND APPLICATION TO THREE-AXIS HYDRAULIC SIMULATOR 被引量:1
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作者 YU Jinying ZHAO Keding CAO Jian 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第3期383-386,共4页
In order to meet tracking performance index of three-axis hydraulic simulator, based on classical quantitative feedback theory (QFT), an improved QFT technique is used to synthesize controller of low gain and bandwi... In order to meet tracking performance index of three-axis hydraulic simulator, based on classical quantitative feedback theory (QFT), an improved QFT technique is used to synthesize controller of low gain and bandwidth. By choosing a special nominal plant, the improved method assigns relative magnitude and phase tracking error between system uncertainty and nominal control plant. Relative tracking error induced by system uncertainty is transformed into sensitivity problem and relative tracking error induced by nominal plant forms into a region on Nichols chart. The two constraints further form into a combined bound which is fit for magnitude and phase loop shaping. Because of leaving out pre-filter of classical QFT controller structure, tracking performance is enhanced greatly. Furthermore, a cascaded two-loop control strategy is proposed to heighten control effect. The improved technique's efficacy is validated by simulation and experiment results. 展开更多
关键词 Three-axis hydraulic simulator quantitative feedback theory(QFT) Cascaded two-loop
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腙基席夫碱配体铜(Ⅱ)配合物的合成、结构表征、生物活性和密度泛函理论计算
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作者 Bhattacharjee Maitri Boruah Smriti Rekha +4 位作者 Dutta Purkayastha R.N. Maniukiewicz Waldemar Chowdhury Shubhamoy Maiti Debasish Akhtar Tamanna 《无机化学学报》 SCIE CAS CSCD 北大核心 2024年第7期1409-1422,共14页
以甲醇为介质,合成了3种新的席夫碱配体HL^(1)(2-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)、HL^(2)(4-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)和L^(3)(2-methoxybenzaldehyde2-(2-oxo-1... 以甲醇为介质,合成了3种新的席夫碱配体HL^(1)(2-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)、HL^(2)(4-hydroxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)和L^(3)(2-methoxybenzaldehyde2-(2-oxo-1,2-diphenylethylidene)hydrazone)的Cu(Ⅱ)配合物1-3。通过元素分析、光谱方法、磁化率测量和密度泛函理论(DFT)计算对配合物进行了表征。通过单晶X射线衍射研究对合成的配体进行了结构表征。通过DFT计算确定了配合物的优化结构。通过紫外可见吸收光谱和荧光发射光谱研究了配合物与小牛胸腺DNA(CT-DNA)的结合能力。吸收光谱研究揭示了增色效应,并提出了与CT-DNA相互作用的可能模式。溴化乙锭(EB)竞争结合研究表明,配合物可以取代DNA-EB加合物中的DNA,且配合物可能以嵌入模式与CTDNA结合。配合物对革兰氏阴性肺炎克雷伯菌、大肠杆菌、鲍氏志贺菌和革兰氏阳性金黄色葡萄球菌的体外抗菌活性研究表明,配合物2对肺炎克雷伯菌和鲍氏志贺菌具有明显抗菌活性,但配合物1和3没有表现出任何显著的抗菌活性。 展开更多
关键词 Cu()配合物 席夫碱 结构 生物活性 密度泛函理论
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聚集诱导发光铂(Ⅱ)配合物对硝基芳烃的高效发光检测
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作者 操青松 曾欣 +7 位作者 王晓理 刘佳铭 闫国胜 王光辉 张宇豪 狄玲 邢杨 凌江华 《发光学报》 EI CAS CSCD 北大核心 2024年第2期364-373,共10页
合成了一例三苯胺基团修饰的铂(Ⅱ)配合物PtppyTPA,并详细地表征了其结构及光物理性质。研究表明,三苯胺基团可有效激活PtppyTPA的聚集诱导发光(AIE)性能,使其在含水量为50%的乙腈中呈现显著的发光增强。以AIE活性的PtppyTPA为发光探针... 合成了一例三苯胺基团修饰的铂(Ⅱ)配合物PtppyTPA,并详细地表征了其结构及光物理性质。研究表明,三苯胺基团可有效激活PtppyTPA的聚集诱导发光(AIE)性能,使其在含水量为50%的乙腈中呈现显著的发光增强。以AIE活性的PtppyTPA为发光探针实现了对4种硝基芳烃包括硝苯地平(Nifedipine,NFD)、5-氯-2-硝基三氟甲苯(5-chloro-2-nitrotrifluorotoluene,ClNTFT)、4-溴-1-氟-2-硝基苯(4-bromo-1-fluoro-2-nitrobenzene,BrFNBz)及3-硝基三氟甲苯(3-nitrotrifluorotoluene, NTFT)的发光检测,利用Stern-Volmer方程拟合检测数据并计算了检测效率及检测限。PtppyTPA对上述硝基芳烃的检测效率分别为11.12,0.27,0.25,0.21 L/mmol;检测限分别为7.1,291.0,314.3,374.2μmol/L。PtppyTPA对NFD具有最高的检测效率和最低的检测限。前线轨道能级及光谱交叠实验表明,PtppyTPA对NFD、ClNTFT、BrFNBz及NTFT的检测机理为电子转移。 展开更多
关键词 铂()配合物 聚集诱导发光 硝苯地平 发光猝灭 密度泛函理论
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可逆SCSC转变中铜(Ⅱ)配合物的可视变色:结构对颜色的影响
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作者 齐继 朱建安 +2 位作者 张延旭 杨嘉豪 张春婷 《大学化学》 CAS 2024年第3期43-57,共15页
设计了一个以单晶-单晶(SCSC)转变这种新的固相无机合成方法为核心的8学时综合化学实验。首先采用直接加成法分别合成了粉末形态与大单晶形态的绿色配合物(H_(3)O)[K(15C5)_(2)][CuCl_(4)](1),其在温度诱导下转变为红色配合物[K(15C5)_(... 设计了一个以单晶-单晶(SCSC)转变这种新的固相无机合成方法为核心的8学时综合化学实验。首先采用直接加成法分别合成了粉末形态与大单晶形态的绿色配合物(H_(3)O)[K(15C5)_(2)][CuCl_(4)](1),其在温度诱导下转变为红色配合物[K(15C5)_(2)][CuCl_(3)](2),这是由于在固相中[K(15C5)_(2)]^(+)的空间位阻效应限制了[CuCl_(3)]−的二聚。并且配合物2在盐酸蒸气诱导下经过SCSC转变恢复为配合物1。配合物1和2之间的SCSC转变也可以通过文字或图画颜色可逆变化的形式在滤纸上呈现,反应迅速,实验现象直观明显,有助于激发学习兴趣。进而,学生可以根据学过的本科无机化学中涉及的晶体场理论内容判断出两种配合物颜色的差异是因为铜(Ⅱ)的配位数不同而导致,有效地促进其将理论知识应用于实践中。通过单晶X射线衍射、粉末X射线衍射、紫外-可见光谱和傅里叶红外变换光谱等对产品进行表征,结果表明,配合物1和2晶型不同而且单晶转化完全,该过程锻炼了学生对剑桥晶体结构数据库的使用,有助于提升学生的数据分析能力和规范安全操作大型仪器的科学素养。本实验学时安排紧凑,可进行模块化教学,试剂成本低廉,适合在化学及相关专业的本科实验教学中推广。 展开更多
关键词 单晶-单晶转变 铜()配合物 空间位阻效应 晶体场理论 综合化学实验
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Quantitative description of characteristics of high-capacity channels in unconsolidated sandstone reservoirs using in situ production data 被引量:15
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作者 Wang Xuezhong Wang Jianyong +2 位作者 Wang Chuanfei Zeng Liufang Liu Xuewei 《Petroleum Science》 SCIE CAS CSCD 2010年第1期106-111,共6页
Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the field of reservoir development. This paper pr... Quantitative description of the high-capacity channels in unconsolidated sandstone reservoirs, into which water was injected to improve oil recovery, is a hot topic in the field of reservoir development. This paper presents a novel approach to describing quantitatively the characteristics of connected macropores in unconsolidated sandstone reservoirs using in situ production data. Based on physical simulation for formation mechanisms of high capacity channels and interwell tracer test data, a mathematical model was established to describe high-capacity channels by grey correlation theory, flow mechanism of fluid in porous media and reservoir engineering, and a program was developed to describe quantitatively the channel characteristics. The predicted results were consistent with field monitoring data (80%), so this model could be economically and effectively used to identify high-capacity channels. 展开更多
关键词 High-capacity channel unconsolidated sandstone quantitative description physical simulation interwell tracer grey correlation theory
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Quantitative Correlation of Chromatographic Retention and Acute Toxicity for Alkyl(1-phenylsulfonyl) Cycloalkane Carboxylates and Their Structural Parameters by DFT 被引量:7
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作者 WANGZun-Yao HANXiang-Yun WANGLian-Sheng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第7期851-857,740,共8页
Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alk... Twenty eight alkyl(1-phenylsulfonyl) cycloalkane carboxylates were computed at the B3LYP/6-31G* level. Based on linear solvation energy theory, two quantitative correlation equations of the molecular structures of alkyl(1-phenylsulfonyl) cycloalkane carboxylate com- pounds to their chromatographic retention (capacity factor lgKW) and the toxicity for photo- bacterium phosphoreum (–lgEC50) were developed by using the molecular structural parameters as theoretical descriptors (r2 = 0.9501, 0.9488). The two quantitative correlation equations were consequently cross validated by leave-one-out (LOO) validation method with q2 of 0.9113 and 0.9281, respectively. The result showed that the two equations achieved in this work by B3LYP/6-31G* are both more advantageous than those from AM1, and can be used to predict the lgKW and –lgEC50 of congeneric organics. 展开更多
关键词 chromatographic retention acute toxicity photobacterium density functional theory method linear solvation energy theory quantitative structure-property relationship (QSPR) quantitative structure-activity relationships (QSAR)
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Quantitative Correlation of the Acute Toxicity of Phenylthio-carboxylates with Their Structural and Thermodynamic Parameters by DFT Calculation 被引量:2
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作者 韩香云 王遵尧 杨春生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第2期145-150,共6页
Phenylthio-carboxylates were computed at the B3LYP/6-31G* level with DFT method. Based on linear solvation energy theory, the structural parameters were firstly taken as theoretical descriptors, and the correspondin... Phenylthio-carboxylates were computed at the B3LYP/6-31G* level with DFT method. Based on linear solvation energy theory, the structural parameters were firstly taken as theoretical descriptors, and the corresponding linear solvation energy relationship (LSER) equation (r = 0.8989) to the toxicity of photobacterium phosphoreum (–lgEC50) was thus obtained. Then the structural and thermodynamic parameters were taken as theoretical descriptors, and as a result the other corresponding correlation equation (r = 0.9274) relating to –lgEC50 was provided. The two equations achieved in this work by B3LYP/6-31G* are both more advantageous than that from AM1. 展开更多
关键词 acute toxicity linear solvation energy theory DFT method quantitative structure-activity relationships (QSAR) aquatic life
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水溶液环境下Phe→Mg(Ⅱ)配合物对映异构的理论研究 被引量:1
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作者 董雷刚 杨应 +4 位作者 黄筱珂 李鹤 王佐成 姜春旭 赵丽红 《江西师范大学学报(自然科学版)》 CAS 北大核心 2023年第4期412-423,共12页
采用密度泛函理论的M06-2X和MN15方法,结合处理溶剂效应的SMD模型方法,研究了在水溶液环境下苯丙氨酸二价镁配合物(Phe→Mg(Ⅱ))的对映异构.研究发现:Phe→Mg(Ⅱ)的对映异构可在质子以羰基O为桥、以羰基O和氨基N联合为桥和只以氨基N为... 采用密度泛函理论的M06-2X和MN15方法,结合处理溶剂效应的SMD模型方法,研究了在水溶液环境下苯丙氨酸二价镁配合物(Phe→Mg(Ⅱ))的对映异构.研究发现:Phe→Mg(Ⅱ)的对映异构可在质子以羰基O为桥、以羰基O和氨基N联合为桥和只以氨基N为桥迁移的3个反应通道上实现.计算结果表明:质子只以氨基N为桥迁移的反应通道最具优势,在只考虑水的极性作用时速度决定步骤的自由能垒为212.3 kJ·mol^(-1),在水的极性和水分子(簇)的共同作用下该自由能垒降至108.1~111.5 kJ·mol^(-1).在水溶液环境下Phe→Mg(Ⅱ)的对映异构过程比较缓慢,苯丙氨酸二价镁可短期用于生命体同补苯丙氨酸和金属镁. 展开更多
关键词 苯丙氨酸 Mg() 配合物 密度泛函理论 溶剂效应 对映异构 自由能垒
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An Approach for Integrating Quantitative Decision Model with Qualitative Judgment
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作者 Zhu Shijing(Institute of Systems Engineerin,Huazhong University of Science and Technology, Wuhan 430074, P. R. China)Wang Xianjia(Department of Hydraulic Power Engineering,Wuhan University of Hydraulic and Electric Engineering, 430072, P. R. C 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 1997年第2期45-52,共8页
In this paper, decision making in complex environment is considered and an approach integrating quantitative decision model with qualitative judgment is proposed. The concept of belief degree for quantitative decision... In this paper, decision making in complex environment is considered and an approach integrating quantitative decision model with qualitative judgment is proposed. The concept of belief degree for quantitative decision model in a complex environment is presented. The integration in formulation and reasoning of quantitative model with qualitative judgment is studied. The combination of various belief degree generated by quantitative model and qualitative judgment is discussed. A decision rule of tradeoff between optimality and belief degree of optimality is proposed. 展开更多
关键词 Decision theory Artificial intelligence quantitative model Qualitative judgment.
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Quantitative Structure-activity Relationship Models of Monomer Reactivity
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作者 YU Xin-Liang YI Xiang YANG Hui-Qiong 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第11期1867-1873,共7页
The reactivity parameters,Q and e,in the Q-e scheme reflect the reactivities of a monomer(or a radical)in free-radical copolymerizations.By applying multiple linear regression(MLR)analysis,the optimal quantitative str... The reactivity parameters,Q and e,in the Q-e scheme reflect the reactivities of a monomer(or a radical)in free-radical copolymerizations.By applying multiple linear regression(MLR)analysis,the optimal quantitative structure-activity relationship(QSAR)model for the reactivity parameter lnQ was developed based on five descriptors(NAF,NOF,EαLUMO,EβHOMO,and EβLUMO)and 69 monomers with the root mean square(rms)error of 0.61.The optimal MLR model of the parameter e obtained from five descriptors(TOcl,NpN,NSO,EαHOMO and DH)and 68 monomers produced rms error of 0.42.Compared with previous models,the two optimal MLR models in this paper show satisfactory statistical characteristics.The feasibility of combining 2D descriptors obtained from the monomers and 3D descriptors calculated from the radical structures(formed from monomers+H )to predict parameters Q and e has been demonstrated. 展开更多
关键词 density FUNCTIONAL theory MOLECULAR DESCRIPTORS multiple linear regression QUANTUM chemical DESCRIPTORS quantitative STRUCTURE-ACTIVITY relationship
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Correlation of Quantitative Structure and Inhibition Phytotoxicity for Aromatic Compounds Using Ab Initio Method
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作者 戴勇 王遵尧 +1 位作者 乔旭 杨春生 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第9期1054-1060,共7页
29 aromatic compounds were computed at the HF/6-31G^* level. Based on linear solvation energy theory firstly, the parameters of molecular structure were taken as theoretical descriptors, and the corresponding linear ... 29 aromatic compounds were computed at the HF/6-31G^* level. Based on linear solvation energy theory firstly, the parameters of molecular structure were taken as theoretical descriptors, and the corresponding linear solvation energy relationship (LSER) (r^2= 0.8993, q^2=0.8559) between the structural parameters and inhibition phytotoxicity to the seed germination rate of cucumis (-lgGC50) was thus obtained. Then the parameters of molecular structure and thermodynamics were taken as theoretical descriptors, and as a result the other corresponding correlation equation (r^2=0.9268, q^2=0.8960) relating to -lgGC50 was achieved. The two equations obtained in this work by HF/6-31G^* are both more advantageous than that from AM 1. 展开更多
关键词 aromatic compounds inhibition phytotoxicity linear solvation energy theory ab initio quantitative structure-activity relationships (QSAR)
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Quantitative Structure-retention Relationship Study of Volatile Components from Rosa Banksiae Ait
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作者 程利平 包晓净 王根礼 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第8期1201-1211,共11页
In the present study,(QSRR) study had been carried out for volatile components from Rosa banksiae Ait.based on various quantum-chemical and physicochemical descriptors derived by B3LYP method.To build QSRR models,a ... In the present study,(QSRR) study had been carried out for volatile components from Rosa banksiae Ait.based on various quantum-chemical and physicochemical descriptors derived by B3LYP method.To build QSRR models,a multiple linear regression (MLR) stepwise method was used.The generated models have good predictive ability and are of high statistical significance with good correlation coefficients (R2≥0.734) and p values far less than 0.05.Preliminary results indicated that the application of the models,especially the prediction of GC retention time and linear retention index of volatile components from Rosa banksiae Ait.,will be helpful.The models contribute also to the identification of important quantum-chemical and physicochemical descriptors responsible for the retention time and linear retention index.It was found that the shape attribute (ShpA) and logP value play a vital role in determining component’s GC retention time and linear retention index which increase with the lipophilicity of volatile components.The larger the shape attribute of analyte is,the larger the deformability is,the stronger the interaction between analyte and stationary phase is,and the longer the GC retention time is,the larger the linear retention index is.The importance of E HOMO,q+,and SEV is also embodied in models,but they are not dominant. 展开更多
关键词 Rosa banksiae Ait. quantitative structure-retention relationship (QSRR) retention time linear retention index density functional theory (DFT)
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Submarine Pipeline Routing Risk Quantitative Analysis
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作者 徐慧 于莉 +1 位作者 胡云昌 王金英 《Transactions of Tianjin University》 EI CAS 2004年第4期304-309,共6页
A new method for submarine pipeline routing risk quantitative analysis was provided, and the study was developed from qualitative analysis to quantitative analysis.The characteristics of the potential risk of the subm... A new method for submarine pipeline routing risk quantitative analysis was provided, and the study was developed from qualitative analysis to quantitative analysis.The characteristics of the potential risk of the submarine pipeline system were considered, and grey-mode identification theory was used. The study process was composed of three parts: establishing the indexes system of routing risk quantitative analysis, establishing the model of grey-mode identification for routing risk quantitative analysis, and establishing the standard of mode identification result. It is shown that this model can directly and concisely reflect the hazard degree of the routing through computing example, and prepares the routing selection for the future. 展开更多
关键词 routing risk quantitative analysis relational difference degree grey subordination degree grey-mode identification theory
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The Application of Relevance Theory in NCEⅡ Teaching
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作者 曹盼盼 《海外英语》 2014年第6X期33-34,36,共3页
New Concept EnglishⅡwith the accurate pronunciation,strong practicality,and many short and interesting stories as its content,has gained a global reputation as the most enduring and the most classic English teaching ... New Concept EnglishⅡwith the accurate pronunciation,strong practicality,and many short and interesting stories as its content,has gained a global reputation as the most enduring and the most classic English teaching materials,which has been fairly popular among a great majority of English learners,especially the beginners.At present there are few researches on NCEⅡteaching,let alone any study from the pragmatics perspective.To have more effective learning and teaching of this book,the relevance theory of cognitive pragmatic plays an essential role. 展开更多
关键词 RELEVANCE theory New CONCEPT English application
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