期刊文献+
共找到904篇文章
< 1 2 46 >
每页显示 20 50 100
Quantitative characterization of reaction behavior between La-bearing FeCrAl melt and CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and its guidance for design of mold flux
1
作者 Lei Fan Tian-peng Qu +1 位作者 De-yong Wang Cheng-jun Liu 《Journal of Iron and Steel Research International》 2025年第3期646-658,共13页
The reaction behavior between CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and La-bearing FeCrAl melt was quantitatively characterized,which was further compared with the reaction behavior of CaO–SiO_(2)-based slags.Bas... The reaction behavior between CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags and La-bearing FeCrAl melt was quantitatively characterized,which was further compared with the reaction behavior of CaO–SiO_(2)-based slags.Based on this,the new type of mold flux for La-bearing FeCrAl alloy continuous casting was designed and its basic properties were evaluated.The results showed that the order of reaction degree of fluxing agents in CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags is(Na_(2)O)>(B_(2)O_(3))>(Li_(2)O),and the percentages of mass change of fluxing agents were 85.8,54.29 and 42.35 wt.%,respectively.Moreover,the addition of(Li_(2)O)and(Na_(2)O)promoted the reaction between(CaO)and[Al],and the reaction degree of the former was weaker than that of the latter,which was due to the greater effect of(Na_(2)O)on the activity of(CaO)and(Al_(2)O_(3))than(Li_(2)O).Compared with the reactivity of CaO–SiO_(2)-based slags,the percentages of mass change of Al and La caused by slag–steel reaction decreased by 10.63–14.36 and 39.78–50.49 wt.%,respectively.The percentages of mass change of(Al_(2)O_(3)),(La_(2)O_(3))and(CaO)in slags highest increased by 17.71,17.98,and 7.81 wt.%,respectively.The reactivity of CaO–Al_(2)O_(3)–La_(2)O_(3)-based slags was significantly weakened.Ultimately,the new type of mold flux was designed and the composition range was determined.The fundamental properties of new mold flux basically meet the theoretical requirements for La-bearing FeCrAl alloy continuous casting. 展开更多
关键词 La-bearing FeCrAl melt CaO-Al_(2)O_(3)-La_(2)O_(3)-based slag Reaction behavior quantitative characterization Mold flux design
原文传递
Quantitative description of characteristics of high-capacity channels in unconsolidated sandstone reservoirs using in situ production data 被引量:16
2
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
原文传递
Enhancing constitutive description and workability characterization of Mg alloy during hot deformation using machine learning-based Arrhenius-type model 被引量:4
3
作者 Jinchuan Long Lei Deng +6 位作者 Junsong Jin Mao Zhang Xuefeng Tang Pan Gong Xinyun Wang Gangfeng Xiao Qinxiang Xia 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第7期3003-3023,共21页
Hot deformation is a commonly employed processing technique to enhance the ductility and workability of Mg alloy.However,the hot deformation of Mg alloy is highly sensitive to factors such as temperature,strain rate,a... Hot deformation is a commonly employed processing technique to enhance the ductility and workability of Mg alloy.However,the hot deformation of Mg alloy is highly sensitive to factors such as temperature,strain rate,and strain,leading to complex flow behavior and an exceptionally narrow processing window for Mg alloy.To overcome the shortcomings of the conventional Arrhenius-type(AT)model,this study developed machine learning-based Arrhenius-type(ML-AT)models by combining the genetic algorithm(GA),particle swarm optimization(PSO),and artificial neural network(ANN).Results indicated that when describing the flow behavior of the AQ80 alloy,the PSO-ANN-AT model demonstrates the most prominent prediction accuracy and generalization ability among all ML-AT and AT models.Moreover,an activation energy-processing(AEP)map was established using the reconstructed flow stress and activation energy fields based on the PSO-ANN-AT model.Experimental validations revealed that this AEP map exhibits superior predictive capability for microstructure evolution compared to the one established by the traditional interpolation methods,ultimately contributing to the precise determination of the optimum processing window.These findings provide fresh insights into the accurate constitutive description and workability characterization of Mg alloy during hot deformation. 展开更多
关键词 Constitutive description Workability characterization Machine learning Mg alloy Hot deformation
在线阅读 下载PDF
Quantitative characterization of vertical zonation of Mesozoic granite weathering reservoirs in the coastal area of eastern Fujian Province,China 被引量:2
4
作者 Jing-Song Hu Yi-Ming Jiang +3 位作者 Hua-Feng Tang Wen-Rui Ma Peng Tao Ning-Yuan Sun 《Petroleum Science》 SCIE EI CSCD 2023年第5期2664-2682,共19页
Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characteriz... Weathering crust reservoirs have obvious vertical zonation,which is the focus of weathering crust reservoir research,but there is a lack of quantitative characterization indexes.To achieve the quantitative characterization of granite weathering crust reservoir and provide the basis for oil exploration of granite weathering crust buried hill reservoir,in this paper,the vertical zonation of granite weathering crust reservoir is quantitatively divided by testing and analyzing the uniaxial compressive strength(UCS),magnetic susceptibility(MS),permeability,and chemical index of alteration(CIA)of the Mesozoic granite weathering crust in the coastal area of eastern Fujian.The results show that the granite weathering crust reservoir can be divided into four zones vertically:a soil zone(SZ),weathered and dissolved zone(WDZ),fracture zone(FZ),and bedrock zone(BZ).A cataclastic area is developed in the FZ and BZ,in which structural fractures are well-developed,the fracture surface density is usually greater than 200 m/m^(2),and the contribution to the fractures in the rock mass is up to about 50%,making this the sweet spot of the reservoir.In the SZ,the rocks are loose,and the pores are well-developed.The UCS is less than 10 MPa,and the average rate of change of the UCS(Δ_(σ))is 0.90.The average permeability is 2823.00 mD,and the average rate of change of the permeability(Δ_(κ))is 5.13.The average CIA is 74.9%.The average clay mineral content is 7%.The rocks in the WDZ have been significantly weathered by physical and chemical processes,and the weathering fractures and dissolution pores are well-developed.The average UCS is 18.2 MPa,and the averageΔ_(σ)is 0.70.The average permeability is 143.80 mD,and averageΔ_(κ)is 4.17.The average CIA is 65.3%.The average clay mineral content is 4%.Under the influence of tectonic movement and physical weathering,the rocks in the FZ have developed structural fractures and a few weathered fractures.The average UCS is 57.9 MPa,and the averageΔ_(σ)is 0.18.The average permeability is 5.50 mD,and the averageΔ_(κ)is 2.55.The average CIA is 61.6%.The average clay mineral content is 2%.In the BZ,the rocks are intact and hard.The average UCS is 69.9 MPa,and the average Ds is 0.13.The average permeability is 1.46 mD,and the averageΔ_(κ)is 1.43.The average CIA is 57.8%.The average clay mineral content is less than 1%.The multi-parameter combination of the UCS,Δ_(σ),permeability,Δ_(κ),CIA,and clay mineral content achieved good results in the division of the zones of the weathering crust.The UCS increases gradually from top to bottom,while Ds,permeability,Δ_(κ),CIA,and clay mineral content all decrease gradually.In addition,based on the petrophysical parameters of the rocks,including the density,resistivity,and acoustic velocity,a good division effect was also achieved,which can provide a basis for the vertical zonation of the granite buried-hill weathering crust reservoir. 展开更多
关键词 Granite weathering crust Vertical zonation of reservoir quantitative characterization Eastern Fujian Mesozoic granite
原文传递
A deep learning-based method for segmentation and quantitative characterization of microstructures in weathering steel from sequential scanning electron microscope images 被引量:1
5
作者 Bing Han Wei-hao Wan +3 位作者 Dan-dan Sun Cai-chang Dong Lei Zhao Hai-zhou Wang 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2022年第5期836-845,共10页
Microstructural classification is typically done manually by human experts,which gives rise to uncertainties due to subjectivity and reduces the overall efficiency.A high-throughput characterization is proposed based ... Microstructural classification is typically done manually by human experts,which gives rise to uncertainties due to subjectivity and reduces the overall efficiency.A high-throughput characterization is proposed based on deep learning,rapid acquisition technology,and mathematical statistics for the recognition,segmentation,and quantification of microstructure in weathering steel.The segmentation results showed that this method was accurate and efficient,and the segmentation of inclusions and pearlite phase achieved accuracy of 89.95%and 90.86%,respectively.The time required for batch processing by MIPAR software involving thresholding segmentation,morphological processing,and small area deletion was 1.05 s for a single image.By comparison,our system required only 0.102 s,which is ten times faster than the commercial software.The quantification results were extracted from large volumes of sequential image data(150 mm^(2),62,216 images,1024×1024 pixels),which ensure comprehensive statistics.Microstructure information,such as three-dimensional density distribution and the frequency of the minimum spatial distance of inclusions on the sample surface of 150 mm^(2),were quantified by extracting the coordinates and sizes of individual features.A refined characterization method for two-dimensional structures and spatial information that is unattainable when performing manually or with software is provided.That will be useful for understanding properties or behaviors of weathering steel,and reducing the resort to physical testing. 展开更多
关键词 Deep learning HIGH-THROUGHPUT Microstructure Sequential image Rapid acquisition quantitative characterization SEGMENTATION
原文传递
Transparent characterization and quantitative analysis of broken gangue's 3D fabric under the bearing compression 被引量:1
6
作者 Junmeng Li Yanli Huang +5 位作者 Shenyang Ouyang Yachao Guo Huadong Gao Laiwei Wu Yibing Shi Lei Zhu 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2022年第2期335-345,共11页
Broken gangue has been extensively used in rockfill dams,subgrade,embankment,foundation cushion and other engineering construction.The deformation characteristics of broken gangue under the bearing compression play a ... Broken gangue has been extensively used in rockfill dams,subgrade,embankment,foundation cushion and other engineering construction.The deformation characteristics of broken gangue under the bearing compression play a decisive role in the firmness,stability and safety of these structures(buildings),and the meso-fabric change of broken gangue under the bearing compression significantly affects its macro deformation.In this study,the transparent characterization and quantitative analysis of 3D fabric of broken gangue under the bearing compression were performed through CT scanning test,image processing and 3D reconstruction technology,and the influence mechanism of internal fabric of broken gangue on its macro deformation was revealed.The results show that:In the loading stage of 0–2 MPa,the sharp corners,thin edges on the blocks and the bar-shaped and blade-shaped blocks with poor regularity are broken first under the bearing compression;in the loading stage of 2–8 MPa,a large number of larger particles in the sample are crushed in the mode of fragmentation;in the loading stage of 8–10 MPa,the breakage degree of samples is relieved.The axial displacement of the block inside the sample occurs,as well as the lateral displacement of the block converging to the central axis of the sample.In the rapid deformation stage,the macro deformation of the broken gangue is mainly caused by the rearrangement and adjustment of the block structure and the breakage of the block;in the slow deformation stage,it is mainly caused by the breakage of the block;in the stable deformation stage,it is mainly caused by the optimization and adjustment of the bearing skeleton in the sample. 展开更多
关键词 Bearing compression Broken gangue 3D fabric Transparent characterization quantitative analysis
在线阅读 下载PDF
Quantitative characterization of tight gas sandstone reservoirs using seismic data via an integrated rock-physics-based framework 被引量:1
7
作者 Zhi-Qi Guo Xiao-Ying Qin Cai Liu 《Petroleum Science》 SCIE EI CAS CSCD 2023年第6期3428-3440,共13页
Seismic characterizing of tight gas sandstone (TGS) reservoirs is essential for identifying promising gas-bearing regions. However, exploring the petrophysical significance of seismic-inverted elastic properties is ch... Seismic characterizing of tight gas sandstone (TGS) reservoirs is essential for identifying promising gas-bearing regions. However, exploring the petrophysical significance of seismic-inverted elastic properties is challenging due to the complex microstructures in TGSs. Meanwhile, interbedded structures of sandstone and mudstone intensify the difficulty in accurately extracting the crucial tight sandstone properties. An integrated rock-physics-based framework is proposed to estimate the reservoir quality of TGSs from seismic data. TGSs with complex pore structures are modeled using the double-porosity model, providing a practical tool to compute rock physics templates for reservoir parameter estimation. The VP/VS ratio is utilized to predict the cumulative thickness of the TGS reservoirs within the target range via the threshold value evaluated from wireline logs for lithology discrimination. This approach also facilitates better capturing the elastic properties of the TGSs for quantitative seismic interpretation. Total porosity is estimated from P-wave impedance using the correlation obtained based on wireline log analysis. After that, the three-dimensional rock-physics templates integrated with the estimated total porosity are constructed to interpret microfracture porosity and gas saturation from velocity ratio and bulk modulus. The integrated framework can optimally estimate the parameters dominating the reservoir quality. The results of the indicator proposed based on the obtained parameters are in good agreement with the gas productions and can be utilized to predict promising TGS reservoirs. Moreover, the results suggest that considering microfracture porosity allows a more accurate prediction of high-quality reservoirs, further validating the applicability of the proposed method in the studied region. 展开更多
关键词 Tight gas sandstone reservoirs quantitative reservoir characterization Rock-physics-based framework Microfracture porosity Rock physics template
原文传递
Theoretical Study on Quantitative Characterization of Interlayer Interference in Multi-Layer Commingled Production 被引量:1
8
作者 Pengfei Mu Shaopeng Wang +2 位作者 Jie Tan Hanqing Zhao Li’an Zhang 《Journal of Power and Energy Engineering》 2021年第4期21-29,共9页
X oilfield is a typical layered reservoir with a large vertical span and many oil-bearing formations. There are significant differences in reservoir types and fluid properties among various formations. The interlayer ... X oilfield is a typical layered reservoir with a large vertical span and many oil-bearing formations. There are significant differences in reservoir types and fluid properties among various formations. The interlayer interference is severe in the development process. At present, the interlayer interference research based on dynamic monitoring data cannot meet development adjustment needs. Combined with the field test results, through the indoor physical simulation experiment method, dynamic inversion method, and reservoir engineering method, this paper analyzes the main control factors and interference mechanism of interlayer interference, studies the variation law of interference coefficient, improves and forms the quantitative characteristic Theory of interlayer interference in multi-layer commingled production, and provides theoretical guidance for the total adjustment of the middle strata division in the oilfield. 展开更多
关键词 Thin Interbedded Reservoir Multi-Layer Production Interbedded Interference quantitative characterization Theoretical Research
在线阅读 下载PDF
Quantitative Characterization and Genesis Analysis of Complex Modals of Pore Structure in Alluvial-Fan Sandy Conglomerate Reservoirs 被引量:1
9
作者 Senlin Yin Juan Chen +2 位作者 Yukun Chen Xiaoguang Wang Xuzhuang Zhu 《石油天然气学报》 CAS 2017年第3期1-12,共12页
新疆油田冲积扇砂砾岩储层岩石类型多样,颗粒大小混杂,分选极差,储层孔隙结构具有典型的多种模态特征,即单模态、双模态与复模态等。利用铸体薄片、压汞、恒速压汞资料定量表征了七东1区砂砾岩储层复杂模态孔隙特征以及连通特征,利用多... 新疆油田冲积扇砂砾岩储层岩石类型多样,颗粒大小混杂,分选极差,储层孔隙结构具有典型的多种模态特征,即单模态、双模态与复模态等。利用铸体薄片、压汞、恒速压汞资料定量表征了七东1区砂砾岩储层复杂模态孔隙特征以及连通特征,利用多元回归分析法建立复杂模态孔隙结构储层的识别模型。以此为基础,分析了冲积扇砂砾岩储层孔隙结构复杂模态成因机制。研究表明:单模态储层主要以Ⅰ类储层为主,双模态储层以Ⅱ、Ⅲ类储层为主,复模态储层以Ⅲ类储层为主。从单模态类型到复模态孔喉组合类型,孔隙发育由好变差,由连通较好的网状到连通较差的星点状,面孔率降低,平均孔径减小,孔喉配位数减小。利用已有147块样品统计发现,七东1区下克拉玛依组储层中单模态储层占19%、双模态储层占48%、复模态储层占33%。由此提出不同模态判断标准,建立了储层孔隙结构预测模型,揭示了储层构型、成岩后作用及注水(聚)开发中后期的系列变化等多因素是导致形成复杂模态的原因。 展开更多
关键词 学术期刊 石油天然气 中国 期刊评价 学报 研制工作 项目组
在线阅读 下载PDF
STUDY ON THE SEQUENCE STRUCTURE OF BUTADIENE-STYRENE RUBBER BY ^(13)C-NMR METHOD Ⅲ. QUANTITATIVE CHARACTERIZATION OF SEQUENCE STRUCTURE
10
作者 陈晓农 胡力平 +1 位作者 严宝珍 焦书科 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1990年第3期269-278,共10页
The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae whic... The quantitative description of the sequence structure of emulsion-processed SBR and solution-processed SBR (by lithium catalyst)was carried out based on their spectral data Of ^(13)C-NMR.The calculating formulae which could be used to obtain diad concentration from the peak intensifies of carbon spectra, average block length, average number of block, and the microstructure composition of the molecular chain were derived. The quantitative result showed that on the molecular chain styrene unit had the tendency to attach to trans-1,4 butadiene unit. The calculated result of the microstructure was in good agreement with that obtained through IR measurement. 展开更多
关键词 Sequence structure quantitative characterization SBR diad concentration average block length average number of block.
在线阅读 下载PDF
Research on Bribery Characterization of Property Developers in Land Market: Based on Quantitative Analysis
11
作者 Hongxia ZHANG Shukui TAN +1 位作者 Li XIA Chunhong JIANG 《Asian Agricultural Research》 2015年第12期52-58,共7页
Taking Wuhan,Nanjing and Guangzhou as examples and using Logistic model and Moran index,this paper made a quantitative analysis on bribery characterization of developers in land market. It found that( i) bribery behav... Taking Wuhan,Nanjing and Guangzhou as examples and using Logistic model and Moran index,this paper made a quantitative analysis on bribery characterization of developers in land market. It found that( i) bribery behavior of developers is promoted by supply and demands;( ii) bribery behavior of developers takes on regional agglomeration and difference. It reached following conclusions:( i) under the influence of macro factors and micro factors,bribery behavior of developers is rational selection after full consideration of institutional environment and corporate strength,and is passive to a certain extent;( ii) bribery behavior of developers has certain spatial correlation,and the high-high correlation characteristic is most significant. 展开更多
关键词 LAND MARKET Property DEVELOPERS BRIBERY characterization quantitative analysis
在线阅读 下载PDF
“Second quantitative characterization”and its application in fractured-vuggy carbonate reservoirs
12
作者 LI Yong DENG Xiaojuan +4 位作者 NING Chaozhong WANG Qi CUI Shiti ZHANG Qi WAN Xiaoguo 《Petroleum Exploration and Development》 CSCD 2022年第4期797-809,共13页
The Ordovician fracture-vug carbonate reservoirs of Tarim Basin,are featured by developed vugs,caves and fractures.The strong heterogeneity results in huge uncertainty when these reservoirs are quantitatively characte... The Ordovician fracture-vug carbonate reservoirs of Tarim Basin,are featured by developed vugs,caves and fractures.The strong heterogeneity results in huge uncertainty when these reservoirs are quantitatively characterized using merely static seismic data.The effective quantitative characterization of the reservoirs has been an urgent problem to be solved.This study creatively proposes the"second quantitative characterization"technique with the combination of dynamic and static data based on the primary static quantitative characterization and fully considering lots of key influence factors when conducting characterization.In this technique,dynamic analysis methods such as well testing,production rate transient analysis,dynamic reserve evaluation and dynamic connectivity evaluation are used to get understandings on this kind of reservoir.These understandings are used as statistical parameters to constrain the inversion of seismic wave impedance to improve the relationship between wave impedance and porosity and determine the fracture-vug morphology,calculate dynamic reserves,and then a more accurate fracture-vugmodel can be selected and used to calculate the oil-water contact inversely based on the results of"second quantitative characterization".This method can lower the uncertainties in the primary quantitative characterization of fracture-vug reservoirs,enhance the accuracy of characterization results significantly,and has achieved good application results in the fracture-vug carbonate reservoirs of Tarim Basin. 展开更多
关键词 Tarim Basin ORDOVICIAN CARBONATE fracture-vug reservoir uncertainty static quantitative characterization dynamic analysis combination of dynamic and static data second quantitative characterization
在线阅读 下载PDF
A Quantitative Method for Characterizing Transport Capability of Compound Hydrocarbon Carrier System 被引量:4
13
作者 雷裕红 罗晓容 +2 位作者 张立宽 程明 宋成鹏 《Journal of Earth Science》 SCIE CAS CSCD 2013年第3期328-342,共15页
The occurrence of hydrocarbon migration in petroliferous basins depends on the balance of driving force and resistance of carriers, which restricts mostly the quantity and positions of hydrocarbon accumulation. The dr... The occurrence of hydrocarbon migration in petroliferous basins depends on the balance of driving force and resistance of carriers, which restricts mostly the quantity and positions of hydrocarbon accumulation. The driving forces of hydrocarbon migration have been quantitatively studied, whereas the migration pathways and carriers were only qualitatively discussed up to now. Establishing a compound hydrocarbon carrier system and quantitatively characterizing its transport capability are significant for understanding the dynamic process of hydrocarbon migration and revealing the hydrocarbon accumulation characteristics. It has become an innovatory trend and also a difficult topic in study of hydrocarbon migration. In this article, a method is described for using displacement pressure to quantitatively characterize the transport capability of the compound carrier system, which composed of sandstone carriers, unconformities and faults. When the weathered and leached zone rarely developed, the basal conglomerate or transgressive sandstone of unconformities can be treated as part of sandstone carriers. An empirical relationship among core porosity, air permeability, and the pore aperture radius corresponding to a mercury saturation of 10% (r 10 ) can be obtained by multiple regression. Using porosity and permeability inversed by seismic data, the displacement pressure of sandstone carriers can be calculated by the empirical relationship and Washburn Equation. Displacement pressure of fault plane can be estimated by the regression formula between fault opening index (FOI) and hydrocarbon column height it can support. This method is applied in the eastern part of south slope in Dongying (东营) depression, Bohai (渤海) Bay Basin, China, to quantitatively characterize thetransport capability of the compound carrier system of Shahejie (沙河街) Formation. The results have good agreement with data from drilling wells. This method may be a step further in study of compound hydrocarbon carrier system in petroliferous basins. It may provide the basis of coupling expulsion quantity, migration driving force and hydrocarbon carrier system to simulate hydrocarbon migration and accumulation. Therefore this will help predict hydrocarbon migration pathways and the locations ofhydrocarbon accumulation. 展开更多
关键词 hydrocarbon carrier system quantitative characterization transport capability Dongying depression displacement pressure.
原文传递
Studies on a Novel Characteristic Atom-pair Holographic Code Applied to Quantitative Structure-chromatographic Retention Relationship of Organic Compounds 被引量:1
14
作者 ZHOU Peng TIAN Fei-Fei +1 位作者 WANG Jiao-Na LI Zhi-Liang 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第11期1337-1342,共6页
6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond len... 6 Atomic fragment types of organic compound have been defined, and the multilevel atom-pair frequency matrix has been constructed according to the occurrence number in pairs of atomic fragments with different bond lengths in the molecule. On the basis of them, a novel molecular coding technique: characteristic atom-pair holographic code (CAHC), is obtained. To some extent, this method exhibits a large number of benefits at the same time. For example, it can calculate 2D molecular topological descriptor easily, operate without difficulty and possess definite physicochemical meaning of 3D molecular structural characterization methods, and may fetch the complicated information of molecule, etc. Therefore, it is appropriate for the study on quantitative structure-property/activity relationship (QSPR/QSAR) of medicines and biological molecules. We attempt in this paper to utilize the method of CAHC to the quantitative prediction of reversed-phase liquid chromatogram (RPLC) retention data of 33 purine derivatives and 24 steroids. The fitting multiple correlation coefficient R2, cross-validated multiple correlation coefficient Q2 and predicted ability Q^2 pred over test set's samples of obtained partial least-square (PLS) regression model are respectively 0.990, 0.893 and 0.977, 0.897, 0.941. 展开更多
关键词 characteristic atom-pair holographic code quantitative structure-chromatographic retention relationship characterization of molecular structure partial least-square regression
在线阅读 下载PDF
An Overview of Dynamic Descriptions for Nanoscale Materials in Particulate Photocatalytic Systems from Spatiotemporal Perspectives
15
作者 Jiawei Yan Zhidong Wei +4 位作者 Kai Takagi Masaya Motodate Zhi Jiang Chiaki Terashima Wenfeng Shangguan 《Nano-Micro Letters》 2025年第8期416-448,共33页
Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic ... Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts. 展开更多
关键词 Dynamic description Particulate photocatalytic system Nanoscale photocatalyst Spatiotemporal characterization
在线阅读 下载PDF
Study on Quantitative Character for Anatomy in Tomato Seedling Stem
16
作者 LI Fuheng WEI Liyan YU Longfeng QI Donglai ZHANG Da 《Journal of Northeast Agricultural University(English Edition)》 CAS 2009年第1期14-18,共5页
The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and t... The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and the cell population in an unit area (mm^2) of no vascular bundle areas were similar and there had small difference among three varieties. On the foundation of these studies, the developmental mechanism of tomato seedling stem was discussed. 展开更多
关键词 Lycopersicun esculentum STEM anatomic structure quantitative character DEVELOPMENT
在线阅读 下载PDF
Ecological Coupling Analysis and Genetic Effect Evaluation of Quantitative Characters in Lonicera edulis
17
作者 Shibo LAN 《Agricultural Biotechnology》 CAS 2015年第1期6-8,15,共4页
Lonicera edulis is a perennial berry shrub that prefers the cold and wet climate, with high nutritional and medicinal value. In this study, ecological cou- pling capability of L. edulis with light, heat, water and soi... Lonicera edulis is a perennial berry shrub that prefers the cold and wet climate, with high nutritional and medicinal value. In this study, ecological cou- pling capability of L. edulis with light, heat, water and soil resources in cold regions was investigated to analyze comprehensively ecological effects of quantitative characters and genetic effects of parents, aiming at providing a theoretical basis for the breeding, introduction and domestication of fine varieties of L. edulis in cold regions of China. The results showed that fruit characters in L. edulis exhibited certain variations among different habitat types. To be specific, fruit vertical diame- ter varied slightly, fruit horizontal diameter varied greatly and seed number varied maximally, with the average variance coefficients of 9.38%, 11.92% and 20. 64%, respectively; in addition, fruit characters in L. edtdis exhibited moderate herilability, moderate genetic gain and low level of genetic differentiation; the heritability of fruit vertical diameter, fruit horizontal diameter and seed number was 0.825, 0. 559 and 0. 627, respectively; the genetic gain of these three fruit characters was 7.53%, 5.72% and 11. 94%, respectively, resulting in significant economical benefits. 展开更多
关键词 Lonicera edulis Ecological coupling quantitative character Genetic effects Genetic gain HERITABILITY
在线阅读 下载PDF
Application of the Quantitative Descriptive Analysis in Cosmetics Sensory Evaluation
18
作者 Jiang Ligang He Yanjie +1 位作者 Chen Bin Huang Jiefang 《China Detergent & Cosmetics》 2018年第3期52-58,共7页
The sensory evaluation method was introduced so late in China, and a complete system of this method has not built yet in cosmetics industry. In this article, the application of the Quantitative Descriptive Analysis me... The sensory evaluation method was introduced so late in China, and a complete system of this method has not built yet in cosmetics industry. In this article, the application of the Quantitative Descriptive Analysis method in the evaluation of the sensory assessment items are studied. With the SPSS reliability analysis, it was found that the Quantitative Descriptive Analysis method is not suitable for some sensory assessment items. 展开更多
关键词 COSMETICS sensory evaluation quantitative descriptive analysis method
在线阅读 下载PDF
A Comparison of the Characterization Between “The Story of an Hour” and “The Unicorn in the Garden”
19
作者 刘颖 张丽芳 《海外英语》 2020年第3期207-210,215,共5页
Flash fiction is a kind of mini-sized story that contains no more than 1,000 words.This kind of fiction emerged alongwith the development of the times.Due to its short length,simple plot and limited words,it focuses o... Flash fiction is a kind of mini-sized story that contains no more than 1,000 words.This kind of fiction emerged alongwith the development of the times.Due to its short length,simple plot and limited words,it focuses on shaping the personality ofcharacters.Both the two flash fictions,"The Story of an Hour"and"The Unicorn in the Garden",express a similar theme of mar-riage,but they employ different ways to create characters.With a detailed comparison of the characters and the characterization be-tween the two works,this paper intends to explore the methods of shaping characters from point of view,psychological descriptionand language description. 展开更多
关键词 flash FICTION characterization point of view PSYCHOLOGICAL description language description
在线阅读 下载PDF
Revisiting support optimization at the Driskos tunnel usinga quantitative risk approach 被引量:5
20
作者 J.Connor Langford N.Vlachopoulos M.S.Diederichs 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2016年第2期147-163,共17页
With the scale and cost of geotechnical engineering projects increasing rapidly over the past few decades,there is a clear need for the careful consideration of calculated risks in design.While risk is typically dealt... With the scale and cost of geotechnical engineering projects increasing rapidly over the past few decades,there is a clear need for the careful consideration of calculated risks in design.While risk is typically dealt with subjectively through the use of conservative design parameters,with the advent of reliability-based methods,this no longer needs to be the case.Instead,a quantitative risk approach can be considered that incorporates uncertainty in ground conditions directly into the design process to determine the variable ground response and support loads.This allows for the optimization of support on the basis of both worker safety and economic risk.This paper presents the application of such an approach to review the design of the initial lining system along a section of the Driskos twin tunnels as part of the Egnatia Odos highway in northern Greece.Along this section of tunnel,weak rock masses were encountered as well as high in situ stress conditions,which led to excessive deformations and failure of the as built temporary support.Monitoring data were used to validate the rock mass parameters selected in this area and a risk approach was used to determine,in hindsight,the most appropriate support category with respect to the cost of installation and expected cost of failure.Different construction sequences were also considered in the context of both convenience and risk cost. 展开更多
关键词 Driskos tunnel quantitative risk analysis Rock mass characterization Underground suppor Reliability-based design FLYSCH
在线阅读 下载PDF
上一页 1 2 46 下一页 到第
使用帮助 返回顶部