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基于参数化的玻壳模具关键成型数据计算机辅助设计计算
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作者 方忆湘 刘文学 黄风山 《现代制造工程》 CSCD 北大核心 2003年第8期41-43,共3页
结合彩色玻壳模具计算机辅助设计计算系统的开发 ,介绍产品或工程设计中以完成关键设计数据计算为主要目标的参数化设计。
关键词 参数化设计 CAD 彩色玻壳模具 成型数据 工程设计
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集成型空间数据库技术探讨与应用实例 被引量:9
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作者 王春晓 李佳田 +2 位作者 王定勇 刘洪斌 武伟 《遥感技术与应用》 CSCD 2003年第2期109-114,共6页
集成型空间数据库的构建过程中,常涉及到空间数据的非结构化特征问题。总结了目前克服此问题的两种技术,即面向对象技术与中间件技术,并对商业化中间件中的空间数据引擎作了标准性、存储结构与图层管理三方面分析。给出了采用空间数据... 集成型空间数据库的构建过程中,常涉及到空间数据的非结构化特征问题。总结了目前克服此问题的两种技术,即面向对象技术与中间件技术,并对商业化中间件中的空间数据引擎作了标准性、存储结构与图层管理三方面分析。给出了采用空间数据引擎的应用实例,提出了急需解决的问题。 展开更多
关键词 成型空间数据 非结构化特征 数据库管理系统 地理信息系统
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城市道路交通事故信息系统空间数据库设计
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作者 李娜 李元军 齐华 《计算机应用》 CSCD 北大核心 2008年第S2期226-229,232,共5页
有效的空间数据库存储结构是实现以集成型数据管理方式为基础的应用系统的关键问题之一,它将决定整个系统的功能和效率。按照为用户的数据视图建模、定义实体及其关系、选择地理表达方式、匹配到Geodatabase元素、组织Geodatabase结构... 有效的空间数据库存储结构是实现以集成型数据管理方式为基础的应用系统的关键问题之一,它将决定整个系统的功能和效率。按照为用户的数据视图建模、定义实体及其关系、选择地理表达方式、匹配到Geodatabase元素、组织Geodatabase结构和制定数据库存储方案等六个步骤对城市道路交通事故信息系统之空间数据库进行了规范化设计。设计所得的空间数据库接近于其逻辑数据模型。分析结果表明,该设计方法有利于优化实现城市道路交通事故信息系统的系统功能。 展开更多
关键词 空间数据 成型数据管理方式 规范化设计
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基于Solidworks软件的快速成型制造技术的研究与应用
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作者 孙忠刚 骆锐 吴沁 《科技信息》 2012年第1期50-51,共2页
Solidworks是常用的机械设计CAD软件,快速成型制造技术能将Solidworks软件设计的三维实体模型快速地制作成零件或者模具,也可以利用快速成形件当作母模,翻制金属模具来制造产品样品。本文论述了Solidworks软件与快速成型软件数据对接方... Solidworks是常用的机械设计CAD软件,快速成型制造技术能将Solidworks软件设计的三维实体模型快速地制作成零件或者模具,也可以利用快速成形件当作母模,翻制金属模具来制造产品样品。本文论述了Solidworks软件与快速成型软件数据对接方法以及成型精度的控制方法。 展开更多
关键词 SOLIDWORKS 快速模具制造 数据对接:成型精度
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Improved Parallel Processing Function for High-Performance Large-Scale Astronomical Cross-Matching 被引量:2
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作者 赵青 孙济州 +3 位作者 于策 肖健 崔辰州 张啸 《Transactions of Tianjin University》 EI CAS 2011年第1期62-67,共6页
Astronomical cross-matching is a basic method for aggregating the observational data of different wavelengths. By data aggregation, the properties of astronomical objects can be understood comprehensively. Aiming at d... Astronomical cross-matching is a basic method for aggregating the observational data of different wavelengths. By data aggregation, the properties of astronomical objects can be understood comprehensively. Aiming at decreasing the time consumed on I/O operations, several improved methods are introduced, including a processing flow based on the boundary growing model, which can reduce the database query operations; a concept of the biggest growing block and its determination which can improve the performance of task partition and resolve data-sparse problem; and a fast bitwise algorithm to compute the index numbers of the neighboring blocks, which is a significant efficiency guarantee. Experiments show that the methods can effectively speed up cross-matching on both sparse datasets and high-density datasets. 展开更多
关键词 astronomical cross-matching boundary growing model HEALPix task partition data-sparse problem
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Retrieve Sea Surface Salinity Using Principal Component Regression Model Based on SMOS Satellite Data 被引量:5
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作者 ZHAO Hong LI Changjun +2 位作者 LI Hongping LV Kebo ZHAO Qinghui 《Journal of Ocean University of China》 SCIE CAS 2016年第3期399-406,共8页
The sea surface salinity(SSS) is a key parameter in monitoring ocean states. Observing SSS can promote the understanding of global water cycle. This paper provides a new approach for retrieving sea surface salinity fr... The sea surface salinity(SSS) is a key parameter in monitoring ocean states. Observing SSS can promote the understanding of global water cycle. This paper provides a new approach for retrieving sea surface salinity from Soil Moisture and Ocean Salinity(SMOS) satellite data. Based on the principal component regression(PCR) model, SSS can also be retrieved from the brightness temperature data of SMOS L2 measurements and Auxiliary data. 26 pair matchup data is used in model validation for the South China Sea(in the area of 4?–25?N, 105?–125?E). The RMSE value of PCR model retrieved SSS reaches 0.37 psu(practical salinity units) and the RMSE of SMOS SSS1 is 1.65 psu when compared with in-situ SSS. The corresponding Argo daily salinity data during April to June 2013 is also used in our validation with RMSE value 0.46 psu compared to 1.82 psu for daily averaged SMOS L2 products. This indicates that the PCR model is valid and may provide us with a good approach for retrieving SSS from SMOS satellite data. 展开更多
关键词 sea surface salinity retrieved algorithm SMOS principle component regression
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Accessing Alignments of Ontologies via IoT Based on SKOS Data Model 被引量:3
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作者 Xiulei Liu Xia Hou +3 位作者 Junyang Yu Ying Gao Yue Zhang Yingying Zhang 《China Communications》 SCIE CSCD 2017年第6期137-155,共19页
Many ontologies are provided to representing semantic sensors data.However,heterogeneity exists in different sensors which makes some service operators of Internet of Thing(IoT) difficult(such as such as semantic infe... Many ontologies are provided to representing semantic sensors data.However,heterogeneity exists in different sensors which makes some service operators of Internet of Thing(IoT) difficult(such as such as semantic inferring,non-linear inverted index establishing,service composing) .There is a great deal of research about sensor ontology alignment dealing with the heterogeneity between the different sensor ontologies,but fewer solutions focus on exploiting syntaxes in a sensor ontology and the pattern of accessing alignments.Our solution infers alignments by extending structural subsumption algorithms to analyze syntaxes in a sensor ontology,and then combines the alignments with the SKOS model to construct the integration sensor ontology,which can be accessed via the IoT.The experiments show that the integration senor ontology in the SKOS model can be utilized via the IoT service,and the accuracy of our prototype,in average,is higher than others over the four real ontologies. 展开更多
关键词 semantic sensor sensor ontologyalignment SKOS 10T
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Spatial data mining system for ore-forming prediction 被引量:1
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作者 Man WANG Linfu XUE Yingwei WANG 《Global Geology》 2007年第1期100-104,共5页
The authors designed the spatial data mining system for ore-forming prediction based on the theory and methods of data mining as well as the technique of spatial database,in combination with the characteristics of geo... The authors designed the spatial data mining system for ore-forming prediction based on the theory and methods of data mining as well as the technique of spatial database,in combination with the characteristics of geological information data.The system consists of data management,data mining and knowledge discovery,knowledge representation.It can syncretize multi-source geosciences data effectively,such as geology,geochemistry,geophysics,RS.The system digitized geological information data as data layer files which consist of the two numerical values,to store these files in the system database.According to the combination of the characters of geological information,metallogenic prognosis was realized,as an example from some area in Heilongjiang Province.The prospect area of hydrothermal copper deposit was determined. 展开更多
关键词 ore-forming prediction spatial data mining multi-source geoscience data
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Prediction of Vapor-Liquid Equilibria of Alcohol-Hydrocarbon Systems by ^1H NMR and Azeotropic Point 被引量:1
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作者 许映杰 姚加 +2 位作者 姚萍 李浩然 韩世钧 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2010年第3期455-461,共7页
With the energy parameters obtained from1H nuclear magnetic resonance(NMR)chemical shifts data by local composition model and coupled with azeotropic point,the low-pressure vapor-liquid equilibrium is satisfactorily p... With the energy parameters obtained from1H nuclear magnetic resonance(NMR)chemical shifts data by local composition model and coupled with azeotropic point,the low-pressure vapor-liquid equilibrium is satisfactorily predicted for alcohol+hexane,alcohol+cyclohexane,and alcohol+benzene binary systems at different temperatures.The relationship between the spectroscopic information and thermodynamic property is presented. 展开更多
关键词 vapor-liquid equilibrium ^1H nuclear magnetic resonance azeotropic point local composition alcohol-hydrocarbon system
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UG环境中汽轮机叶片汽道建模方法
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作者 付贵言 《机械工程师》 2006年第6期111-111,共1页
介绍了采用UG生成汽轮机汽道时叶片汽道型线的特点和叶片型线分类,分别介绍了数据点成型和圆弧线成型的建模方法。
关键词 UG 汽轮机叶片 汽道 数据成型 圆弧线成型
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The development of real time data driving multi-axis linkage and synergic movement control system of 3D variable cross-section roll forming machine 被引量:2
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作者 管延智 Li Qiang +2 位作者 Wang Haibo Yang Zhenfeng Zheng Yuting 《High Technology Letters》 EI CAS 2013年第3期261-266,共6页
The three dimensional variable cross-section roll forming is a kind of new metal forming technol- ogy which combines large forming force, multi-axis linkage movement and space synergic movement, and the sequential syn... The three dimensional variable cross-section roll forming is a kind of new metal forming technol- ogy which combines large forming force, multi-axis linkage movement and space synergic movement, and the sequential synergic movement of the ganged roller group is used to complete the metal sheet forming according to the shape of the complicated and variable forming part data. The control system should meet the demands of quick response to the test requirements of the product part. A new kind of real time data driving multi-axis linkage and synergic movement control strategy of 3D roll forming is put forward in the paper. In the new control strategy, the forming data are automatically generated according to the shape of the parts, and the multi-axis linkage movement together with cooperative motion among the six stands of the 3D roll forming machine is driven by the real-time information, and the control nodes are also driven by the forming data. The new control strategy is applied to a 48 axis 3D roll forming machine developed by our research center, and the control servo period is less than 10ms. A forming experiment of variable cross section part is carried out, and the forming preci- sion is better than + 0.5mm by the control strategy. The result of the experiment proves that the control strategy has significant potentiality for the development of 3D roll forming production line with large scale, multi-axis ganged and svner^ic movement 展开更多
关键词 real time data driving variable cross-section roll forming multi-axis ganged synergic movement
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An Empirical Study of China's Energy- Intensive Industries' Growth Based on Environmental Total Factor Productivity
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《China Economist》 2012年第2期37-49,共13页
Using directional distance function and nonparametric data envelopment analys&, th& paper estimates the environmental total factor productivity (ETFP) of energy-intensive industries in China from 1995 to 2010, and... Using directional distance function and nonparametric data envelopment analys&, th& paper estimates the environmental total factor productivity (ETFP) of energy-intensive industries in China from 1995 to 2010, and performs an empirical analysis on factors affecting ETFP growth after studying the differences of energy-intensive industries ' ETFP by industries and provinces. The findings include the following: energy-intensive industries 'ETFP growth is mainly driven by technical progress; China, at its current development stage, still has the potential to raise the productivity of its energy- intensive industries. By estimating the provincial data, we find that the ETFP growth of different provinces converge at different levels. Further market liberalization, increased FDl flows and reductions in energy intensity will help to improve each province's ETFP growth. In addition, increasing investment in energy saving and emissions reduction and improving corporate environmental management capacity can help to reduce a company's short-term cost of complying with environmental regulations. 展开更多
关键词 energy-intensive industries environmental pollution environmental total factorproductivity (TEFP) directional distance functionJEL: D24 047 Q55
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The Choice of Model of External Load in Problem of Synthesis of Adequate Mathematical Description
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《Journal of Mathematics and System Science》 2012年第8期489-493,共5页
The problem of mathematical simulation of motion of dynamic systems characteristics and their coincidence with real experimental data which correspond to these characteristics is investigated in this paper. Mathematic... The problem of mathematical simulation of motion of dynamic systems characteristics and their coincidence with real experimental data which correspond to these characteristics is investigated in this paper. Mathematical description of process will be named as adequate mathematical description if the results of mathematical simulation by the help of this description coincide with experiment with inaccuracy of initial data. The synthesis of such description is very important at mathematical modeling and forecast of motion of real physical phenomena. The specified problem is still poorly investigated and hardly adapted to formalization. The requirements to the adequate mathematical description of dynamic system are considered for the case when mathematical description of dynamic systems is represented by linear system of the ordinary differential equations. In this paper the mathematical model of process is given a priori with inexact parameters and then the models of external loads are being determined for which the results of simulation coincide with experiment. The methods of obtaining of the steady models of external loads are suggested. The example of the adequate description construction of the main mechanical line dynamics of rolling mill is given. 展开更多
关键词 Dynamic systems adequate description external load identification.
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Framework Design of Eco-Technology Evaluation Platform and Integration System
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作者 肖玉 谢高地 甄霖 《Journal of Resources and Ecology》 CSCD 2017年第4期325-331,共7页
Global ecological degradation is a matter of enormous concern. In the early 20 st century, the United States, Europe and China began to apply eco-technology to ecosystem management and restoration in order to slow dow... Global ecological degradation is a matter of enormous concern. In the early 20 st century, the United States, Europe and China began to apply eco-technology to ecosystem management and restoration in order to slow down or stop ecological degradation. To date, there has been neither a systematic summary and scientific evaluation, nor is there a unified platform to describe ecological degradation problems in different areas and existing eco-technologies. These shortcomings have hindered the popularization and application of technologies. This study intends to build an eco-technology evaluation platform and integration system that brings together heterogeneous data from multiple sources. The key technology of the eco-technology evaluation platform and integration system is information integration technology. We will establish a metadata engine based on metadata storage to achieve access to and integration of metadata and heterogeneous data sources. The information integration mode based on a metamodel addresses information heterogeneity at four levels: system, syntax, structure and semantics. We develop the framework for an eco-technology evaluation platform and integration system to integrate ecotechnology databases, eco-technology evaluation model databases, eco-technology evaluation parameter databases and spatial databases of ecological degradation and eco-technology with metadata and metamodel integration mode. This system can support functions for the query and display of global and typical ecological degradation and the query, display, evaluation and prioritization of eco-technologies, which can realize the visualization of global and Chinese ecological degradation and eco-technology evaluation and prioritization. This system will help government decision makers and relevant departments to understand ecological degradation and the effects of ecotechnology implementation. 展开更多
关键词 eco-technology evaluation eco-technology prioritization integrated system METADATA METAMODEL
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Predicting Soil Moisture Characteristic Curves from Continuous Particle-Size Distribution Data 被引量:17
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作者 M.H.MOHAMMADI F.MESKINI-VISHKAEE 《Pedosphere》 SCIE CAS CSCD 2013年第1期70-80,共11页
Soil moisture characteristic curve (SMC) is a fundamental soil property and its direct measurement is tedious and time consuming. Therefore, various indirect methods have been developed to predict SMC from particle-... Soil moisture characteristic curve (SMC) is a fundamental soil property and its direct measurement is tedious and time consuming. Therefore, various indirect methods have been developed to predict SMC from particle-size distribution (PSD). However, the majority of these methods often yield intermittent SMC data because they involve estimating individual SMC points. The objectives of this study were 1) to develop a procedure to predict continuous SMC from a limited number of experimental PSD data points and 2) to evaluate model predictions through comparisons with measured values. In this study, an approach that allowed predicting SMC from the knowledge of PSD, parameterized by means of the closed-form van Genuchten model (VG), was used. Through using Mohammadi and Vanclooster (MV) model, the parameters obtained from fitting of VG to PSD data were applied to predict SMC curves. Since the residual water content (Or) could not be obtained through fitting of VG-MV integrated model to PSD data, we also examined and compared four different methods estimating 0r. Results showed that the proposed equation (MV-VG integrated model) provided an excellent fit to all the PSD data and the model could adequately predict SMC as measured in forty-two soils sampled from different regions of Iran. For all soils, the method in which Or Was obtained through parameter optimization procedure provided the best overall predictions of SMC. The two methods estimating Or with Campbell and Shiozawa (CS) model resulted in less accuracy than the optimization procedure. Furthermore, the proposed model underestimated the moisture content in the dry range of SMC when the value of 0r was assumed to equal zero. 0r could be attributed to the incomplete desorption of water coated on soil particles and the accurate estimation of 0r was critical in prediction of SMC, especially for fine-textured soils at high suction heads. It could be concluded that the advantages of our approach were the continuity, robustness, and independency of model performance on soil type, allowing to improve predictions of SMC from PSD at the field and watershed scales. 展开更多
关键词 fine-textured soils modeling residual water content soil hydraulic properties van Genuchten model
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Thermal control system of Alpha Magnetic Spectrometer 被引量:3
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作者 CUI Zheng LUO Feng +1 位作者 WANG NaiHua CHENG Lin 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第10期2553-2562,共10页
Since its installation on the International Space Station(ISS)in mid-May 2011,the Alpha Magnetic Spectrometer(AMS)has spent over two years on orbit,fully operational,collecting an enormous amount of data including the... Since its installation on the International Space Station(ISS)in mid-May 2011,the Alpha Magnetic Spectrometer(AMS)has spent over two years on orbit,fully operational,collecting an enormous amount of data including the temperatures from the on-board 1118 sensors for thermal control.A large database is continuously updated and analyzed to understand the thermal behavior of the experiment in the space environment and its interaction with the ISS.This paper specifies the design,building,analysis and testing of the thermal control system and its various components for an overview of the AMS thermal control system and its space environment.Also given are some examples of analysis and correlation of the space environmental and ISS parameters with the thermal behaviors of various AMS components. 展开更多
关键词 AMS thermal control system thermal design SIMULATION orbital operations
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The Effect of Corporate Governance on Debt Financing Cost of Listed Companies 被引量:2
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作者 LI Lin DONG Fangyu +2 位作者 LIU Yifang HUANG Haijun WANG Shouyang 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2016年第3期772-788,共17页
In recent years, bank credit business is booming with the increasing borrowing retention o~ China's listed companies, and debt financing has become the major approach among listed companies' financing strategies. As... In recent years, bank credit business is booming with the increasing borrowing retention o~ China's listed companies, and debt financing has become the major approach among listed companies' financing strategies. As a series of institutional arrangements about rights, responsibilities and benefits between different shareholders, corporate governance mechanism has a significant influence on the cost of debt financing. This paper employs variable coefficient panel data model to investigate the relationship of the listed company's debt financing costs and corporate governance mechanism in terms of structural characteristics and time series characteristics. The results show that optimizing the structure of both Board of Directors and Board of Supervisors, establishing a reasonable management incentive system and reducing the concentration of ownership properly can directly contribute to a lower company's debt financing costs. Meanwhile, property rights have an interactive influence on corporate governance from four aspects, which indirectly effect in company's debt financing costs. 展开更多
关键词 Corporate governance debt financing cost property rights.
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Least-squares reverse-time migration for reflectivity imaging 被引量:7
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作者 YAO Gang WU Di 《Science China Earth Sciences》 SCIE EI CAS CSCD 2015年第11期1982-1992,共11页
A least-squares reverse-time migration scheme is presented for reflectivity imaging. Based on an accurate reflection modeling formula, this scheme produces amplitude-preserved stacked reflectivity images with zero pha... A least-squares reverse-time migration scheme is presented for reflectivity imaging. Based on an accurate reflection modeling formula, this scheme produces amplitude-preserved stacked reflectivity images with zero phase. Spatial preconditioning, weighting and the Barzilai-Borwein method are applied to speed up the convergence of the least-squares inversion. In addition, this scheme compensates the effect of ghost waves to broaden the bandwidth of the reflectivity images. Furthermore, roughness penalty constraint is used to regularize the inversion, which in turn stabilizes inversion and removes high-wavenumber artifacts and mitigates spatial aliasing. The examples of synthetic and field datasets demonstrate the scheme can generate zerophase reflectivity images with broader bandwidth, higher resolution, fewer artifacts and more reliable amplitudes than conventional reverse-time migration. 展开更多
关键词 adjoint migration least-squares reverse-time migration cross-correlation imaging condition deconvolution imagingcondition deghost
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Experimental and computational correlation and prediction on herbicide resistance for acetohydroxyacid synthase mutants to Bispyribac 被引量:2
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《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第3期286-295,共10页
Bispyribac is a widely used herbicide that targets the acetohydroxyacid synthase (AHAS) enzyme. Mutations in AHAS have caused serious herbicide resistance that threatened the continued use of the herbicide. So far, ... Bispyribac is a widely used herbicide that targets the acetohydroxyacid synthase (AHAS) enzyme. Mutations in AHAS have caused serious herbicide resistance that threatened the continued use of the herbicide. So far, a unified model to decipher herb- icide resistance in molecular level with good prediction is still lacking. In this paper, we have established a new QSAR method to construct a prediction model for AHAS mutation resistance to herbicide Bispyribac. A series of AHAS mutants concerned with the herbicide resistance were constructed, and the inhibitory properties of Bispyribac against these mutants were meas- ured. The 3D-QSAR method has been transformed to process the AHAS mutants and proposed as mutation-dependent biom- acromolecular QSAR (MB-QSAR). The excellent correlation between experimental and computational data gave the MB-QSAR/CoMFA model (q2 = 0.615, P = 0.921, F2pred = 0.598) and the MB-QSAR/CoMSIA model (q2 = 0.446, r2 = 0.929, r2pred = 0.612), which showed good prediction for the inhibition properties of Bispyribac against AHAS mutants. Such MB-QSAR models, containing the three-dimensional molecular interaction diagram, not only disclose to us for the first time the detailed three-dimensional information about the structure-resistance relationships, but may also provide further guidance to resistance mutation evolution. Also, the molecular interaction diagram derived from MB-QSAR models may aid the resistance-evading herbicide design. 展开更多
关键词 MB-QSAR resistance prediction herbicide resistance BISPYRIBAC-SODIUM acetohydroxyacid synthase
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The internal structure models of Europa
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作者 JIN Sheng JI JiangHui 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第1期156-161,共6页
We model the interior of Europa using a method by which we set three layers of Europa and the composition of each layer in advance. Comparing the calculated mass and radius related to each model with the data derived ... We model the interior of Europa using a method by which we set three layers of Europa and the composition of each layer in advance. Comparing the calculated mass and radius related to each model with the data derived by the observations, we propose three possible internal structure models for Europa. All models are assumed to be differentiated into a metallic core, a (Mg,Fe)2SiO4 silicate mantle and an outer water shell. The only difference amongst these models are the composition of the core. The core of Model I is composed of Fe, while Model II composed of FeS, and the two models are based on the inferences provided by Europa's external gravitational field. Model III has a core which consists of Fe-FeS alloy, similar to that of Earth's outer core. Model I has a Fe core with a radius of 431 km, a (Mg,Fe)2SiO4 mantle with 999 km and a water shell with 132 km. Model II has a 777 km FeS core, a 619 km (Mg,Fe)2SiO4 mantle and a 167 km water shell. Model III has a 571 km Fe0.8(FeS)0.2 core, a 832 km (Mg,Fe)2SiO4 mantle and a 166 km water shell. In all three models, the density range and the radius of each layer is consistent with those deduced by Anderson et al. 展开更多
关键词 EUROPA internal structure equation of state
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