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让数学思想方法在学生脑海里扎根
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作者 钱守旺 《新教师》 2012年第1期42-45,共4页
从目前的情形看来,广大教师对于在教学中渗透数学思想方法都有了一个初步的认识,但是纵观整个课堂教学,却存在不少问题。那么,我们一线教师面临的教学现状如何?在教学过程中渗透数学思想方法遇到哪些典型问题?学生掌握数学思想方法的程... 从目前的情形看来,广大教师对于在教学中渗透数学思想方法都有了一个初步的认识,但是纵观整个课堂教学,却存在不少问题。那么,我们一线教师面临的教学现状如何?在教学过程中渗透数学思想方法遇到哪些典型问题?学生掌握数学思想方法的程度到底如何?针对教学中遇到的问题与困惑有什么对策?本期专题,我们邀请名师以及知名教研员与您一起探讨。 展开更多
关键词 数学思想方法 问题解决 乘法分配律 教研员 知识的理解 数学知识体系 算理 数学素养 运算律 数量关
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七年级下学期期中复习点拨
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作者 孙琪斌 《中学生数理化(七年级数学)(华师大版)》 2008年第4期9-12,共4页
学习完了一元一次方程、二元一次方程组、一元一次不等式(组)等知识,需要对涉及的重点知识作一总结和归纳,以便灵活运用知识解决问题.
关键词 一元一次不等式 二元一次方程组 一元一次方程 代入消元法 加减消元法 解集 学习过程 模型解 数量关
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Icon memory research under different time pressures and icon quantities based on event-related potential 被引量:5
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作者 牛亚峰 薛澄岐 +3 位作者 李雪松 李晶 王海燕 金涛 《Journal of Southeast University(English Edition)》 EI CAS 2014年第1期45-50,共6页
In order to obtain related brain electrical components and neural bases of physiology assessment of icon elements in a digital human-computer interface the modified sample-delay matching task experimental paradigm is ... In order to obtain related brain electrical components and neural bases of physiology assessment of icon elements in a digital human-computer interface the modified sample-delay matching task experimental paradigm is used under different time pressures 4 000 and 2 000 ms and different icon quantities three five and ten icons on icon memory based on event-related potential ERP technology.Experimental results demonstrate that P300 has significant volatility changes and the maximum amplitude around the middle line of the parietal area PZ and P200 has obvious volatility changes around the middle line of the frontal and central area FCZ during icon cognition.P300 and P200 amplitudes increase as tasks become more difficult.Thus P300 latency is positively correlated with task difficulty. ERP research on the characteristics of icon memory will be an important reference standard in guiding user neurocognitive behavior and physiology assessment on interface usability. 展开更多
关键词 time pressure icon quantity event-related potential ERP
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一道课本习题的开放探究性设计
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作者 袁海峰 《数学学习与研究》 2013年第23期104-104,106,共2页
科学的本质是探索未知,科学的发现来自于探究过程.普通高中数学课程标准提出:"教材的呈现应为引导学生自主探索留有比较充分的空间,有利于学生经历观察、实验、猜测、推理、交流、反思等过程.在进行教学设计时,可以通过设置具有启... 科学的本质是探索未知,科学的发现来自于探究过程.普通高中数学课程标准提出:"教材的呈现应为引导学生自主探索留有比较充分的空间,有利于学生经历观察、实验、猜测、推理、交流、反思等过程.在进行教学设计时,可以通过设置具有启发性、挑战性的问题,激发学生进行思考,鼓励学生自主探索,并在独立思考的基础上进行合作交流,在思考、探索和交流的过程中获得较为全面的体验和理解."数学教学作为科学发现在教学上的一种特殊形式正越来越多地被提倡运用探究性教学. 展开更多
关键词 探究性教学 数学教学 探究过程 函数问题 几何画板 数学科 抽象概括能力 自主探究能力 位线 数量关
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“数”中思“形”,“形”中觅“数”——例谈初中数学数形结合的解题技巧
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作者 高德亮 《数学学习与研究》 2013年第24期108-108,共1页
数与形是数学中的两个最古老,也是最基本的研究对象,两者相互联系,称这为"数形结合"或"形数结合".就初中数学而言,数形结合就是在形象与抽象思维的交叉运用中,以数助形,以形助数,互相促进,协调发展.因此,数形结合... 数与形是数学中的两个最古老,也是最基本的研究对象,两者相互联系,称这为"数形结合"或"形数结合".就初中数学而言,数形结合就是在形象与抽象思维的交叉运用中,以数助形,以形助数,互相促进,协调发展.因此,数形结合思想是学生解决问题中的一种很重要的方法,是把许多知识转化为能力的"桥". 展开更多
关键词 数形结合 解题技巧 问题具体化 分类讨论 平面直角坐标系 绝对值符号 形数 教学实例 辅助线 数量关
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FTIR Spectroscopic Study of Broad Bean Diseased Leaves 被引量:2
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作者 李志永 刘刚 +5 位作者 李伦 欧全宏 赵兴祥 张黎 周湘萍 汪禄祥 《Agricultural Science & Technology》 CAS 2012年第11期2363-2366,2408,共5页
[Objective] The aim was to indentify diseased leaves of broad bean by vibra- tional spectroscopy. [Method] In this paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and norma... [Objective] The aim was to indentify diseased leaves of broad bean by vibra- tional spectroscopy. [Method] In this paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and normal leaves were studied using Fourier transform infrared spectroscopy combined with chemometrics. [Result] The spectra of the samples were similar, only with minor differences in absorption inten- sity of several peaks. Second derivative analyses show that the significant difference of all samples was in the range of 1 200-700 cm2. The data in the range of 1 200- 700 cm' were selected to evaluate correlation coefficients, hierarchical cluster analy- sis (HCA) and principal component analysis (PCA). Results showed that the correla- tion coefficients are larger than 0.928 not only between the healthy leaves, but also between the same diseased leaves. The values between healthy and diseased leaves, and among diseased leaves, are all declined. HCA and PCA yielded about 73.3% and 82.2% accuracy, respectively. [Conclusion] This study demonstrated that FTIR techniques might be used to detect crop diseases. 展开更多
关键词 FTIR spectroscopy Broad bean diseases Principal component analysis Cluster analysis
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数学思想方法在有理数运算中的应用
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作者 金枝焕 《中学生数理化(七年级数学)(北师大版)》 2008年第Z3期69-71,共3页
数学习题浩瀚无边,问题又可变式发散,这样习题就林林总总,题量就千千万万,但是蕴涵在问题中的数学思想方法总是永恒不变的。
关键词 数学思想方法 数学习题 变式 转化思想 数学问题 非负数 数形结合思想 分类讨论思想 运算律 数量关
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数形结合教学思想之我见
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作者 杨俊杰 《数学学习与研究》 2013年第24期110-110,共1页
我国著名数学家华罗庚教授指出:"数形结合百般好,隔裂分家万事非."这句话说明了"数"和"形"是紧密联系的,事实上"数"往往借助于"形","形"往往又离不开"数".经常... 我国著名数学家华罗庚教授指出:"数形结合百般好,隔裂分家万事非."这句话说明了"数"和"形"是紧密联系的,事实上"数"往往借助于"形","形"往往又离不开"数".经常运用数形结合的方法,能帮助学生类比、发掘,解剖其所具有的几何模型,有利于帮助学生深化思维,扩展知识,提高能力.如何让学生在解决数学问题中熟练运用数形结合的方法解决问题呢?我觉得应从以下几方面入手: 展开更多
关键词 数形结合 数学家华罗庚 数学问题 二元一次方程组 二次函数 函数图像 数学思想方法 数学素养 数量关
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如何在教学中找回失落的“数学应用意识”
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作者 刘仁得 《数学学习与研究》 2013年第24期116-116,共1页
近年来受应试教育的影响,致使师生的"数学应用意识"失落,随着数学的应用越来越广泛,数学课程中强化数学的应用意识已成为发达国家的共识,《数学课程新标准》明确规定:"要使学生受到把实际问题抽象成数学问题的训练,形成... 近年来受应试教育的影响,致使师生的"数学应用意识"失落,随着数学的应用越来越广泛,数学课程中强化数学的应用意识已成为发达国家的共识,《数学课程新标准》明确规定:"要使学生受到把实际问题抽象成数学问题的训练,形成应用数学的意识."重视数学应用,将标志着我们的数学教育进一步走向未来、走向世界. 展开更多
关键词 数学应用意识 有理数加法 兴趣小组 帕提侬神庙 现实生活 构造数学 活动课程 程中 运动问题 数量关
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课堂提问应从何入手
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作者 杨平海 《小学教学研究(理论版)》 2014年第2期10-11,共2页
"学贵有疑。"提问能吸引学生的注意,启发学生的思维。为此,在数学教学中,教师应精心设计问题,引导学生带着问题去思考、去领悟。这样,才能开拓学生的思路,使学生产生积极探求解决问题的强烈愿望,准确地掌握学习目标。那么,数... "学贵有疑。"提问能吸引学生的注意,启发学生的思维。为此,在数学教学中,教师应精心设计问题,引导学生带着问题去思考、去领悟。这样,才能开拓学生的思路,使学生产生积极探求解决问题的强烈愿望,准确地掌握学习目标。那么,数学教学中提问应从哪些方面入手呢?1.问在重点处每节课都有它的重点,只有把重点逐一攻克,这节课的教学任务才算基本完成。因此,我们要在教材的重点处设计有坡度。 展开更多
关键词 数学教学 学贵有疑 钝角三角形 异分母分数 教学任务 掌握学习 锐角三角形 解题方法 练习课 数量关
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Quantitative Relationship Between Multi-Angle Polarized Reflectance and BRDF of Rock 被引量:5
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作者 ZHAO Yun-sheng WU Tai-xia +1 位作者 LIU Bao LUO Yang-jie 《Journal of China University of Mining and Technology》 EI 2005年第3期192-196,共5页
The traditional remote sensing mainly detects the ground vertically to obtain the 2D information but it is hard to get adequate parameters for the quantitative remote sensing to invert land features. The multi-angle o... The traditional remote sensing mainly detects the ground vertically to obtain the 2D information but it is hard to get adequate parameters for the quantitative remote sensing to invert land features. The multi-angle observation can get more detailed and reliable 3D structural parameters of targets, so it makes the quantitative remote sensing applicable. During the process of reflecting, scattering and transmitting the electromagnetic wave, minerals and rocks could reveal the polarized features related to the nature of themselves. Therefore, it has become a new approach of quantitative remote sensing to detect multi-angle polarized information of minerals and rocks. In respect that the polarized reflectance always goes with the bidirectional one, we can obtain the 3D spatial distribution of targets by a polarized means together with detecting its bi-directional reflectance. From the perspective of multi-angle polarized remote sensing mechanism, the quantitative relationship between multi-angle polarized reflectance and the BRDF is studied in this paper. And it is testified that the bi-directional reflectance, polarized reflectance of 45° and the mean value of polarized reflectance are equal to that of the corresponding azimuth angle, zenith angle, detection angle and detection channels in 27t space by experiment. 展开更多
关键词 ROCK Multi-angle Polarized reflectance BRDF Quantitative remote sensing
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Quantitative determination of PFC3D microscopic parameters 被引量:3
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作者 LI Zhuo RAO Qiu-hua 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第3期911-925,共15页
It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the mi... It is important to calibrate micro-parameters for applying partied flow code(PFC)to study mechanical characteristics and failure mechanism of rock materials.Uniform design method is firstly adopted to determine the microscopic parameters of parallel-bonded particle model for three-dimensional discrete element particle flow code(PFC3D).Variation ranges of microscopic of the microscopic parameters are created by analyzing the effects of microscopic parameters on macroscopic parameters(elastic modulus E,Poisson ratio v,uniaxial compressive strengthσc,and ratio of crack initial stress to uniaxial compressive strengthσci/σc)in order to obtain the actual uniform design talbe.The calculation equations of the microscopic and macroscopic parameters of rock materials can be established by the actual uniform design table and the regression analysis and thus the PFC3D microscopic parameters can be quantitatively determined.The PFC3D simulated results of the intact and pre-cracked rock specimens under uniaxial and triaxial compressions(including the macroscopic mechanical parameters,stress−strain curves and failure process)are in good agreement with experimental results,which can prove the validity of the calculation equations of microscopic and macroscopic parameters. 展开更多
关键词 quantitative relationship of microscopic and macroscopic parameters uniform design method three-dimensional particle flow code(PFC3D) ROCK
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Quantum Secure Direct Intercommunication with Superdense Coding and Entanglement Swapping 被引量:1
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作者 HUANG Da-Zu GUO Ying ZENG Gui-Hua 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第12期1290-1294,共5页
A quantum secure direct intercommunication scheme is proposed to exchange directly the communicators' secret messages by making ase of swapping entanglement of Bell states. It has great capacity to distribute the sec... A quantum secure direct intercommunication scheme is proposed to exchange directly the communicators' secret messages by making ase of swapping entanglement of Bell states. It has great capacity to distribute the secret messages since these messages have been imposed on high-dimensional Bell states via the local unitary operations with superdense coding. The security is ensured by the secure transmission of the travel sequences and the application of entanglement swapping. 展开更多
关键词 quantum secure direct intercommunication entanglement swapping quantum cryptography
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Volatility-volume relationship of Chinese copper and aluminum futures market 被引量:2
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作者 Bai-sheng SHI Xue-hong ZHU +1 位作者 Hong-wei ZHANG Yi ZENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第12期2607-2618,共12页
Following Bessembinder and Seguins,trading volume is separated into expected and unexpected components.Meanwhile,realized volatility is divided into continuous and discontinuous jump components.We make the empirical r... Following Bessembinder and Seguins,trading volume is separated into expected and unexpected components.Meanwhile,realized volatility is divided into continuous and discontinuous jump components.We make the empirical research to investigate the relationship between trading volume components and various realized volatility using1min high frequency data of Shanghai copper and aluminum futures.Moreover,the asymmetry of volatility-volume relationship is investigated.The results show that there is strong positive correlation between volatility and trading volume when realized volatility and its continuous component are considered.The relationship between trading volume and discontinuous jump component is ambiguous.The expected and unexpected trading volumes have positive influence on volatility.Furthermore,the unexpected trading volume,which is caused by arrival of new information,has a larger influence on price volatility.The findings also show that an asymmetric volatility-volume relationship indeed exists,which can be interpreted by the fact that trading volume has more explanatory power in positive realized semi-variance than negative realized semi-variance.The influence of positive trading volume shock on volatility is larger than that of negative trading volume shock,which reflects strong arbitrage in Chinese copper and aluminum futures markets. 展开更多
关键词 nonferrous metals futures volatility-volume relationship high frequency data trading volume asymmetry
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Correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma 被引量:8
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作者 Shenjiang Li Xiangsheng Xiao +3 位作者 Shiyuan Liu Huimin Li Chengzhou Li Chenshi Zhang 《The Chinese-German Journal of Clinical Oncology》 CAS 2007年第4期345-349,共5页
Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarci... Objective:To evaluate the correlation of the quantifiable parameters of blood flow pattern derived with dynamic CT in solitary bronchogenic adenocarcinoma(SBA).Methods:46 patients with solitary bronchogenic adenocarcinomas (SBA)(diameter≤4 cm)underwent multi-location dynamic contrast material-enhanced(nonionic contrast material was administrated via the antecubital vein at a rate of 4 mL/s by using an autoinjector 90 mL,4×5 mm or 4×2.5 mm scanning mode with stable table were performed)serial CT.Precontrast and postcontrast attenuation on every scan was recorded.Perfusion (PBA),peak height(PHBA),ratio of peak height of the SPN to that of the aorta(BA-to-A ratio)and mean transit time(MTT)were calculated.The correlation between peak height of the aorta(PHA)and parameters of the SBA(PHBA,BA-to-A ratio,PBA,and MTT)and those among parameters of the SBA were assessed by means of linear regression analysis.Regression equation among parameters of the SBA were obtain by means of stepwise regression.Results:The correlation between the SBA peak height(PHBA,36.78 HU±12.02)and the aortic peak height(PHA)was significant(r=0.506,P<0.0001).No significant cor- relation was found between the BA-to-Apeak height ratio(15.33%±4.55)and the aortic peak height(r=0.130,P=0.388> 0.05)as it was between the SBA perfusion(PBA,31.86 mL/min/100 g±9.74)and the aortic peak height(r=0.049,P=0.749 >0.05).The SBA perfusion correlated with the PHBA and the BA-to-A peak height ratio(r=0.394,P=0.007<0.05;r=0.407, P=0.005<0.05).The PHBA correlated positively with the BA-to-A peak height ratio(r=0.781,P<0.0001).Mean transit time was 14.84 s±5.52.PBA=18.500+0.872×BA-to-A ratio.BA-to-A ratio=4.467+0.295×PHBA.Conclusion:The linear correlation between the SBA perfusion and BA-to-Aratio and that between BA-to-Aratio and PHBA can be expressed by equation. It is possible to design a simpler scanning procedure of investigation of bronchogenic adenocarcinoma angiogenesis. 展开更多
关键词 bronchogenic adenocarcinoma blood flow pattern CT quantifiable parameters linear correlation
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QUASI-SYNCHRONOUS MULTICARRIER DS-CDMA USING Z-COMPLEMENTARY SEQUENCES 被引量:1
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作者 Tu Yifeng Fan Pingzhi +1 位作者 Yuan Weina Hao Li 《Journal of Electronics(China)》 2009年第4期487-491,共5页
In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interfer... In this paper, a multicarrier DS-CDMA system which employs Z-Complementary Se- quences (ZCS) as spreading code is investigated. The new system can not only eliminate multipath interference and Multiple Access Interference (MAI), but also support flexible number of users com- pared with system using Orthogonal Complementary (OC) codes. Multicarrier DS-CDMA using OC codes can be regarded as a special case of our proposed system. Zero Correlation Zone (ZCZ) of ZCS can be flexibly adjusted to meet the requirements on the user number and maximum multipath and in- ter-user delay, in this way, more users can be supported without losing interference-free property. The effectiveness of the proposed system is validated through theoretical analysis and simulation results. 展开更多
关键词 Orthogonal Complementary (OC) codes Multicarrier DS-CDMA Z-Complemen-tary Sequences (ZCS) Zero Correlation Zone (ZCZ)
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New autocorrelation topological indexes and their application in QSAR study 被引量:1
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作者 王鹏 杨蕾 +2 位作者 陈春云 高大文 龙明策 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2005年第1期41-43,共3页
Considering the problems of classical structure parameters that existed in the study of quantitative structure activity relationship (QSAR). Two new groups of autocorrelation topological indexes V(t), E(t), (P(t)) and... Considering the problems of classical structure parameters that existed in the study of quantitative structure activity relationship (QSAR). Two new groups of autocorrelation topological indexes V(t), E(t), (P(t)) and A(t), B(t), C(t), D(t) were developed on the basis of molecular topology and autocorrelation function in mathematics. The first group were obtained from Van der Waals volume, electronegativity and topological vertex degree;and the second group were obtained from the different combination of topological vertex degree.Corresponding softwares of ATIJP and ATITP have been developed for calculating these two new groups of indexes. Better results have been obtained from the application of these indexes in QSAR study. 展开更多
关键词 autocorrelation topological index QSAR PREDICTION
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Study of the relationship between acupuncture dose and effect 被引量:6
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作者 Xuemin Shi 《Acupuncture and Herbal Medicine》 2021年第1期3-9,共7页
Acupuncture dose-effect relationship is the essential feature of acupuncture and the key factor of acupuncture’s therapeutic effect.It is a comprehensive category,including needle direction,needle strength,needle dep... Acupuncture dose-effect relationship is the essential feature of acupuncture and the key factor of acupuncture’s therapeutic effect.It is a comprehensive category,including needle direction,needle strength,needle depth,selection of specific techniques,length of time between acupuncture treatment sessions,length of needle retention time,and frequency of treatment,all of which play a decisive role in the curative effect and prognosis of diseases[1]. 展开更多
关键词 ACUPUNCTURE NEEDLE ACUPUNCTURE
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A Quantitative Structure Property Relationship for Prediction of Flash Point of Alkanes Using Molecular Connectivity Indices 被引量:3
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作者 Morteza Atabati Reza Emamalizadeh 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第4期420-426,共7页
Many structure-property/activity studies use graph theoretical indices, which are based on the topological properties of a molecule viewed as a graph. Since topological indices can be derived directly from the molecul... Many structure-property/activity studies use graph theoretical indices, which are based on the topological properties of a molecule viewed as a graph. Since topological indices can be derived directly from the molecular structure without any experimental effort, they provide a simple and straightforward method for property prediction. In this work the flash point of alkanes was modeled by a set of molecular connectivity indices (Х), modified molecular connectivity indices ( ^mХ^v ) and valance molecular connectivity indices ( ^mХ^v ), with ^mХ^v calculated using the hydrogen perturbation. A stepwise Multiple Linear Regression (MLR) method was used to select the best indices. The predicted flash points are in good agreement with the experimental data, with the average absolute deviation 4.3 K. 展开更多
关键词 quantitative structure property relationship flash point molecular connectivity indices hydrogen perturbation ALKANE
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Airborne Pollen Grains Of Afyon, Turkey 被引量:3
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作者 Adem BICAKCI 1, Süheyla ERGUN 2, Sevcan TATLIDIL 1, Hulusi MALYER 1, Sabri ?ZYURT 2, Ahmet AKKAYA 3, Nihat SAPAN 5 Department of Biology, Faculty of Science, University of Uludag, Bursa, Turkey 2. Department of Biology, Faculty of Science, University of Afyon Kocatepe, Afyon Turkey +1 位作者 3. Department of Pulmonology, Faculty of Medicine, University of Süleyman Demirel, Isparta, Turkey 4. Division of Pediatric Allergy, Faculty of Medicine, University of Uludag, Bursa, Turkey) 《Acta Botanica Sinica》 CSCD 2002年第11期1371-1375,共5页
The airborne pollen grains of Afyon have been studied for a two_year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentif... The airborne pollen grains of Afyon have been studied for a two_year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentified ones. Of them, 6 732 were identified in 1999 and 7 635 in 2000. Of the total pollen grains, 69.67% were arboreal, 26.64% non_arboreal and 3.68 % unidentified. The majority of the investigated pollen grains were from Pinus, Gramineae, Cupressaceae, Platanus , Chenopodiaceae/Amaranthaceae, Quercus, Ailanthus, Moraceae, Juglans , Salix, Cedrus and Rosaceae. The highest level of pollen grains was in May. 展开更多
关键词 TURKEY Afyon pollen calendar pollen grains
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