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An Incremental Model Transfer Method for Complex Process Fault Diagnosis 被引量:3
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作者 Xiaogang Wang Xiyu Liu Yu Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第5期1268-1280,共13页
Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of productio... Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of production process often lead to the changes of data distribution and the emergence of new fault classes, and the number of the new fault classes is unpredictable. The reconstruction of the fault diagnosis model and the identification of new fault classes have become core issues under the circumstances. This paper presents a fault diagnosis method based on model transfer learning and the main contributions of the paper are as follows: 1) An incremental model transfer fault diagnosis method is proposed to reconstruct the new process diagnosis model. 2) Breaking the limit of existing method that the new process can only have one more class of faults than the old process, this method can identify M faults more in the new process with the thought of incremental learning. 3) The method offers a solution to a series of problems caused by the increase of fault classes. Experiments based on Tennessee-Eastman process and ore grinding classification process demonstrate the effectiveness and the feasibility of the method. 展开更多
关键词 COMPLEX process FAULT DIAGNOSIS incremental LEARNING model TRANSFER
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Incremental 4D-VAR assimilation scheme based on Lorenz model 被引量:1
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作者 WANG Xidong XU Dongfeng XU Xiaohua 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2008年第z1期93-100,共8页
Four-dimensional variational(4D-VAR) data assimilation method is a perfect data assimilation solution in theory, but the computational issue is quite difficult in operational implementation.The incremental 4D-VAR assi... Four-dimensional variational(4D-VAR) data assimilation method is a perfect data assimilation solution in theory, but the computational issue is quite difficult in operational implementation.The incremental 4D-VAR assimilation scheme is set up in order to reduce the computational cost. It is shown that the accuracy of the observations, the length of the assimilation window and the choice of the first guess have an important influence on the assimilation outcome through the contrast experiment. Compared with the standard 4D-VAR assimilation scheme, the incremental 4D-VAR assimilation scheme shows its advantage in the computation speed through an assimilation experiment. 展开更多
关键词 4D-VAR assimilation incremental 4D-VAR assimilation Lorenz model
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A Spatio-temporal Data Model for Road Network in Data Center Based on Incremental Updating in Vehicle Navigation System 被引量:1
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作者 WU Huisheng LIU Zhaoli +1 位作者 ZHANG Shuwen ZUO Xiuling 《Chinese Geographical Science》 SCIE CSCD 2011年第3期346-353,共8页
The technique of incremental updating,which can better guarantee the real-time situation of navigational map,is the developing orientation of navigational road network updating.The data center of vehicle navigation sy... The technique of incremental updating,which can better guarantee the real-time situation of navigational map,is the developing orientation of navigational road network updating.The data center of vehicle navigation system is in charge of storing incremental data,and the spatio-temporal data model for storing incremental data does affect the efficiency of the response of the data center to the requirements of incremental data from the vehicle terminal.According to the analysis on the shortcomings of several typical spatio-temporal data models used in the data center and based on the base map with overlay model,the reverse map with overlay model (RMOM) was put forward for the data center to make rapid response to incremental data request.RMOM supports the data center to store not only the current complete road network data,but also the overlays of incremental data from the time when each road network changed to the current moment.Moreover,the storage mechanism and index structure of the incremental data were designed,and the implementation algorithm of RMOM was developed.Taking navigational road network in Guangzhou City as an example,the simulation test was conducted to validate the efficiency of RMOM.Results show that the navigation database in the data center can response to the requirements of incremental data by only one query with RMOM,and costs less time.Compared with the base map with overlay model,the data center does not need to temporarily overlay incremental data with RMOM,so time-consuming of response is significantly reduced.RMOM greatly improves the efficiency of response and provides strong support for the real-time situation of navigational road network. 展开更多
关键词 spatio-temporal data model reverse map with overlay model road network incremental updating vehicle navigation system data center vehicle terminal
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Grouping tree species to estimate basal area increment in temperate multispecies forests in Durango,Mexico
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作者 Jaime Roberto Padilla-Martínez Carola Paul +2 位作者 Kai Husmann Jose Javier Corral-Rivas Klaus von Gadow 《Forest Ecosystems》 SCIE CSCD 2024年第1期1-13,共13页
Multispecies forests have received increased scientific attention,driven by the hypothesis that biodiversity improves ecological resilience.However,a greater species diversity presents challenges for forest management... Multispecies forests have received increased scientific attention,driven by the hypothesis that biodiversity improves ecological resilience.However,a greater species diversity presents challenges for forest management and research.Our study aims to develop basal area growth models for tree species cohorts.The analysis is based on a dataset of 423 permanent plots(2,500 m^(2))located in temperate forests in Durango,Mexico.First,we define tree species cohorts based on individual and neighborhood-based variables using a combination of principal component and cluster analyses.Then,we estimate the basal area increment of each cohort through the generalized additive model to describe the effect of tree size,competition,stand density and site quality.The principal component and cluster analyses assign a total of 37 tree species to eight cohorts that differed primarily with regard to the distribution of tree size and vertical position within the community.The generalized additive models provide satisfactory estimates of tree growth for the species cohorts,explaining between 19 and 53 percent of the total variation of basal area increment,and highlight the following results:i)most cohorts show a"rise-and-fall"effect of tree size on tree growth;ii)surprisingly,the competition index"basal area of larger trees"had showed a positive effect in four of the eight cohorts;iii)stand density had a negative effect on basal area increment,though the effect was minor in medium-and high-density stands,and iv)basal area growth was positively correlated with site quality except for an oak cohort.The developed species cohorts and growth models provide insight into their particular ecological features and growth patterns that may support the development of sustainable management strategies for temperate multispecies forests. 展开更多
关键词 Temperate multispecies forests Cluster analysis Basal area increment Generalized additive models
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INCREMENTAL MICRO-MECHANICAL MODEL OF PLAIN WOVEN FABRIC
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作者 ZhangYitong HaoYongjiang LiCuiyu 《Acta Mechanica Solida Sinica》 SCIE EI 2004年第2期131-139,共9页
Warp yarns and weft yarns of plain woven fabric are the principal axes of mate- rial of fabric. They are orthogonal in their original con?guration, but are obliquely crisscross in deformed con?guration in general. I... Warp yarns and weft yarns of plain woven fabric are the principal axes of mate- rial of fabric. They are orthogonal in their original con?guration, but are obliquely crisscross in deformed con?guration in general. In this paper the expressions of incremental components of strain tensor are derived, the non-linear model of woven fabric is linearized physically and its geometric non-linearity survives. The convenience of determining the total deformation is shown by the choice of the coordinate system of the principal axes of the material, with the convergence of the incremental methods illustrated by examples. This incremental model furnishes a basis for numerical simulations of fabric draping and wrinkling based on the micro-mechanical model of fabric. 展开更多
关键词 micro-weaving structure MICRO-MECHANICS incremental constitutive model prin- cipal axes of material woven fabric incremental methods
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A Modular Incremental Model for English Full Parsing
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作者 孟遥 Li +4 位作者 Sheng Zhao Tiejun Zhang Jing 《High Technology Letters》 EI CAS 2003年第2期57-60,共4页
In this paper, we present a modular incremental statistical model for English full parsing. Unlike other full parsing approaches in which the analysis of the sentence is a uniform process, our model separates the full... In this paper, we present a modular incremental statistical model for English full parsing. Unlike other full parsing approaches in which the analysis of the sentence is a uniform process, our model separates the full parsing into shallow parsing and sentence skeleton parsing. In shallow parsing, we finish POS tagging, Base NP identification, prepositional phrase attachment and subordinate clause identification. In skeleton parsing, we use a layered feature-oriented statistical method. Modularity possesses the advantage of solving different problems in parsing with corresponding mechanisms. Feature-oriented rule is able to express the complex lingual phenomena at the key point if needed. Evaluated on Penn Treebank corpus, we obtained 89.2% precision and 89.8% recall. 展开更多
关键词 incremental statistical model shallow parsing skeleton parsing feature-oriented rule
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Pore water pressure increment model for saturated Nanjing fine sand subject to cyclic loading 被引量:6
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作者 Wang Binghui Chen Guoxing Jin Dandan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第4期569-576,共8页
Three groups of dynamic triaxial tests were performed for saturated Nanjing fine sand subjected to uniform cyclic loading. The tested curves of the excess pore water pressure (EPWP) ratio variation with the ratio of... Three groups of dynamic triaxial tests were performed for saturated Nanjing fine sand subjected to uniform cyclic loading. The tested curves of the excess pore water pressure (EPWP) ratio variation with the ratio of the number of cycles are provided. The concept of the EPWP increment ratio is introduced and two new concepts of the effective dynamic shear stress ratio and the log decrement of effective stress are defined. It is found that the development of the EPWP increment ratio can be divided into three stages: descending, stable and ascending. Furthermore, at the stable and ascending stages, a satisfactory linear relationship is obtained between the accumulative EPWP increment ratio and natural logarithm of the effective dynamic shear stress ratio. Accordingly, the EPWP increment ratio at the number of cycles N has been deduced that is proportional to the log decrement of effective stress at the cycle number N-l, but is independent of the cyclic stress amplitude. Based on the analysis, a new EPWP increment model for saturated Nanjing fine sand is developed from tested data fitting, which provides a better prediction of the curves of EPWP generation, the number of cycles required for initial liquefaction and the liquefaction resistance. 展开更多
关键词 cyclic loading Nanjing fine sand EPWP model EPWP increment ratio effective dynamic shear stress ratio logarithmic decrement of effective stress
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A STATISTICAL PREDICTION MODEL FOR SPRING RAINFALL OVER NORTHERN CHINA BASED ON THE INTERANNUAL INCREMENT APPROACH 被引量:6
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作者 范可 《Journal of Tropical Meteorology》 SCIE 2012年第4期543-550,共8页
The spring (March-April-May) rainfall over northern China (SPRNC) is predicted by using the interannual increment approach. DY denotes the difference between the current year and previous years. The seasonal forecast ... The spring (March-April-May) rainfall over northern China (SPRNC) is predicted by using the interannual increment approach. DY denotes the difference between the current year and previous years. The seasonal forecast model for the DY of SPRNC is constructed based on the data that are taken from the 1965-2002 period (38 years), in which six predictors are available no later than the current month of February. This is favorable so that the seasonal forecasts can be made one month ahead. Then, SPRNC and the percentage anomaly of SPRNC are obtained by the predicted DY of SPRNC. The model performs well in the prediction of the inter-annual variation of the DY of SPRNC during 1965-2002, with a correlation coefficient between the predicted and observed DY of SPRNC of 0.87. This accounts for 76% of the total variance, with a low value for the average root mean square error (RMSE) of 20%. Both the results of the hindcast for the period of 2003-2010 (eight years) and the cross-validation test for the period of 1965-2009 (45 years) illustrate the good prediction capability of the model, with a small mean relative error of 10%, an RMSE of 17% and a high rate of coherence of 87.5% for the hindcasts of the percentage anomaly of SPRNC. 展开更多
关键词 spring rainfall over northern China statistical prediction model interannual increment approach
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Sandbox Modeling of the Fault-increment Pattern in Extensional Basins 被引量:6
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作者 Geng Changbo Tong Hengmao +1 位作者 He Yudan Wei Chunguang 《Petroleum Science》 SCIE CAS CSCD 2007年第2期29-34,共6页
Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major bo... Three series of sandbox modeling experiments were performed to study the fault-increment pattern in extensional basins. Experimental results showed that the tectonic action mode of boundaries and the shape of major boundary faults control the formation and evolution of faults in extensional basins. In the process of extensional deformation, the increase in the number and length of faults was episodic, and every 'episode' experienced three periods, strain-accumulation period, quick fault-increment period and strain-adjustment period. The more complex the shape of the boundary fault, the higher the strain increment each 'episode' experienced. Different extensional modes resulted in different fault-increment patterns. The horizontal detachment extensional mode has the 'linear' style of fault-increment pattern, while the extensional mode controlled by a listric fault has the 'stepwise' style of fault-increment pattern, and the extensional mode controlled by a ramp-flat boundary fault has the 'stepwise-linear' style of fault-increment pattern. These fault-increment patterns given above could provide a theoretical method of fault interpretation and fracture prediction in extensional basins. 展开更多
关键词 Extensional basin sandbox modeling fault-increment pattern boundary fault
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Maximum Power Point Tracking Using the Incremental Conductance Algorithm for PV Systems Operating in Rapidly Changing Environmental Conditions 被引量:1
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作者 Derek Ajesam Asoh Brice Damien Noumsi Edwin Nyuysever Mbinkar 《Smart Grid and Renewable Energy》 2022年第5期89-108,共20页
Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV pane... Maximum Power Point Tracking (MPPT) is an important process in Photovoltaic (PV) systems because of the need to extract maximum power from PV panels used in these systems. Without the ability to track and have PV panels operate at its maximum power point (MPP) entails power losses;resulting in high cost since more panels will be required to provide specified energy needs. To achieve high efficiency and low cost, MPPT has therefore become an imperative in PV systems. In this study, an MPP tracker is modeled using the IC algorithm and its behavior under rapidly changing environmental conditions of temperature and irradiation levels is investigated. This algorithm, based on knowledge of the variation of the conductance of PV cells and the operating point with respect to the voltage and current of the panel calculates the slope of the power characteristics to determine the MPP as the peak of the curve. A simple circuit model of the DC-DC boost converter connected to a PV panel is used in the simulation;and the output of the boost converter is fed through a 3-phase inverter to an electricity grid. The model was simulated and tested using MATLAB/Simulink. Simulation results show the effectiveness of the IC algorithm for tracking the MPP in PV systems operating under rapidly changing temperatures and irradiations with a settling time of 2 seconds. 展开更多
关键词 modelING SIMULATION PV System Maximum Power Point Tracking (MPPT) incremental Conductance Algorithm MATLAB/SIMULINK
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Species-specific,pan-European diameter increment models based on data of 2.3 million trees
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作者 Mart-Jan Schelhaas Geerten M Hengeveld +11 位作者 Nanny Heidema Esther Thurig Brigitte Rohner Giorgio Vacchiano Jordi Vayreda John Redmond Jaroslaw Socha Jonas Fridman Stein Tomter Heino Polley Susana Barreiro Gert-Jan Nabuurs 《Forest Ecosystems》 SCIE CSCD 2018年第3期277-295,共19页
Background: Over the last decades, many forest simulators have been developed for the forests of individual European countries. The underlying growth models are usually based on national datasets of varying size, obta... Background: Over the last decades, many forest simulators have been developed for the forests of individual European countries. The underlying growth models are usually based on national datasets of varying size, obtained from National Forest Inventories or from long-term research plots. Many of these models include country-and location-specific predictors, such as site quality indices that may aggregate climate, soil properties and topography effects. Consequently, it is not sensible to compare such models among countries, and it is often impossible to apply models outside the region or country they were developed for. However, there is a clear need for more generically applicable but still locally accurate and climate sensitive simulators at the European scale, which requires the development of models that are applicable across the European continent. The purpose of this study is to develop tree diameter increment models that are applicable at the European scale, but still locally accurate. We compiled and used a dataset of diameter increment observations of over 2.3 million trees from 10 National Forest Inventories in Europe and a set of 99 potential explanatory variables covering forest structure, weather, climate, soil and nutrient deposition.Results: Diameter increment models are presented for 20 species/species groups. Selection of explanatory variables was done using a combination of forward and backward selection methods. The explained variance ranged from10% to 53% depending on the species. Variables related to forest structure(basal area of the stand and relative size of the tree) contributed most to the explained variance, but environmental variables were important to account for spatial patterns. The type of environmental variables included differed greatly among species.Conclusions: The presented diameter increment models are the first of their kind that are applicable at the European scale. This is an important step towards the development of a new generation of forest development simulators that can be applied at the European scale, but that are sensitive to variations in growing conditions and applicable to a wider range of management systems than before. This allows European scale but detailed analyses concerning topics like CO2 sequestration, wood mobilisation, long term impact of management, etc. 展开更多
关键词 European forests Diameter increment model Climate change Growth modelling National forest inventory
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Cost-Benefit Assessment of Inspection and Repair Planning for Ship Structures Considering Corrosion Model Uncertainty
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作者 李典庆 唐文勇 张圣坤 《China Ocean Engineering》 SCIE EI 2005年第3期409-420,共12页
Owing to high costs and unnecessary inspections necessitated by the traditional inspection planning for ship structures, the risk-based inspection and repair planning should be investigated for the most cost-effective... Owing to high costs and unnecessary inspections necessitated by the traditional inspection planning for ship structures, the risk-based inspection and repair planning should be investigated for the most cost-effective inspection. This paper aims to propose a cost-benefit assessment model of risk-based inspection and repair planning for ship structures subjected to corrosion deterioration. Then, the benefit-cost ratio is taken to be an index for the selection of the optimal inspection and repair strategy. The planning problem is formulated as an optimization problem where the benefit-cost ratio for the expected lifetime is maximized with a constraint on the minimum acceptalbe reliability index. To account for the effect of corrosion model uncertainty on the cost-benefit assessment, two corrosion models, namgly, Paik' s model and Guedes Soares' model, are adopted for analysis. A numerical example is presented to illustrate the proposed method. Sensitivity studies are also providet. The results indicate that the proposed method of risk-based cost-benefit analysis can effectively integrate the economy with reliability of the inspection and repair planning. A balance can be achieved between the risk cost and total expected inspection and repair costs with the proposed method, which is very. effective in selecting the optimal inspection and repair strategy. It is pointed out that the corrosion model uncertainty and parametric uncertaintg have a significant impact on the cost-benefit assessment of inspection and repair planning. 展开更多
关键词 ship structures inspection and repair planning cost-benefit model uncertainty
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Model of Cost-benefit Flow in Six Green Projects in China
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作者 ZhuYongjie ZhouBoling 《Forestry Studies in China》 CAS 2003年第3期49-53,共5页
From the point of cost-benefit flow and with the Six Green Projects in China as the case and background, it is criticized that the current natural resource and environmental management and the policies in China have s... From the point of cost-benefit flow and with the Six Green Projects in China as the case and background, it is criticized that the current natural resource and environmental management and the policies in China have some problems unsolved since the model of cost-benefit flow is still centralized and mainly in an administrative way in spite of many efforts made theoretically and practically. It is suggested that a new model based on market-oriented economy from the point of cost-benefit flow with Six Green Projects Management and Policies System consist of complete natural reserve (NR). Management system included environmental nature reserves in addition to biodiversity nature reserve, paid using nature resources, an environmental conservation and construction industry and renewable resource production incentive system that turn the direct administration and operation to management and services. The detail figure of the new model of cost-benefit flow is provided and the main points related are discussed in this paper. 展开更多
关键词 Six Green Projects model of cost-benefit flow management and policy frame
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“Products-Knowledge” Two-Dimensional Increment Model of Fashion Industry Value Chain Based on Industry Analysis
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作者 刘畅 黄震宇 《Journal of Donghua University(English Edition)》 EI CAS 2016年第4期660-664,共5页
Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes t... Fashion industry has a complex characteristic for it spans the first, second, and third industries. In addition, the characteristic of creative industry has high value-added for its knowledge outputting, which makes the traditional value-added analysis based on supply chain not easy and good enough to interpret its industry value-added features. From the perspective of "products-knowledge" two-dimensional analysis,a fashion industry value chain increment model is built,by simulating the process of "product flow" and "information flow" value-added. The fashion industry value chain increment model provides an effective way for the enterprise strategy formulation and production strategy adjustment. 展开更多
关键词 fashion formulation adjustment creative return ledge increment enough manufacture itself
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热液成矿系统构造控矿理论 被引量:8
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作者 杨立强 杨伟 +6 位作者 张良 高雪 申世龙 王偲瑞 徐瀚涛 贾晓晨 邓军 《地学前缘》 EI CAS CSCD 北大核心 2024年第1期239-266,共28页
构造对成矿的控制是热液成矿系统的典型特征之一,系统剖析多重尺度控矿构造的几何学、运动学、动力学、流变学和热力学对认识矿床成因和预测找矿至关重要;而如何实现控矿构造格架、渗透性结构、成矿流体通道和矿化变形网络由静态到多尺... 构造对成矿的控制是热液成矿系统的典型特征之一,系统剖析多重尺度控矿构造的几何学、运动学、动力学、流变学和热力学对认识矿床成因和预测找矿至关重要;而如何实现控矿构造格架、渗透性结构、成矿流体通道和矿化变形网络由静态到多尺度时-空四维动态的转变,查明流体通道和矿床增量生长过程与控制因素,揭示热液成矿系统的构造-流体耦合成矿机制和定位规律是亟待解决的关键科学难题。为此,我们在对已有相关成果系统梳理的基础上,提出了科学构建热液成矿系统构造控矿理论的基本要点与对应方法及应用范畴:(1)流体而非构造是构造控矿理论的中心,热液系统的流体流动与成矿作用受控于断裂带格架及其渗透性结构,其中渗透率是将流体流动与流体压力变化联系起来理解控矿构造的核心;(2)不同控矿构造组合的关键控制是构造差应力和流体压力的大小,而矿化类型的变化可能是由于构造应力场引起的容矿构造方位的不同和赋矿围岩之间的强度差异所致;(3)流体通道的生长始于超压流体储库上游围岩中孤立的微裂隙沿流体压力梯度最大的方向、随裂隙发育且相互连结而形成新的长裂隙,并最终连通形成断裂网络内的流体通道,矿床的增量生长发生在高流体通量的短爆发期,断层反复滑动驱动其内流体压力、流速和应力快速变化,当由此诱发的流体通道生长破坏了流体系统的动态平衡时,随之而来的流体快速降压就成为金属沉淀成矿的关键驱动因素;(4)以热液裂隙-脉系统野外地质观测和构造-蚀变-矿化网络三维填图为基础,通过宏观与微观各级控矿构造相结合、地质历史与构造应力分析相结合、局部与区域点-线-面相结合、浅部与深部相结合、时间与空间相结合、定性和定量相结合,对各种控矿因素开展多学科、多尺度、多层次、全方位综合研究,是应遵循的基本原则;(5)通过构造-蚀变-矿化网络填图,将蚀变-矿化体与控矿构造的类型、形态、规模、产状和间距等几何学特征联系起来,利用热液裂隙-脉系统和断裂网络拓扑学及矿体三维几何结构分析等定量方法查明控矿构造格架和渗透性结构并揭示矿化变形网络的连通性与成矿潜力;(6)合理构建地质模型,选取合适的热力学参数和动力学边界条件,利用HCh和COMSOL等方法,定量模拟成矿过程中的流体流动、热-质传递、应力变形和化学反应等的时-空变化,是揭示构造-流体耦合成矿机理和定位规律、预测矿化中心和确定找矿目标的有效途径。进而提出了构造控矿理论的研究流程:聚焦构造-流体耦合成矿机制和定位规律这一关键科学问题,选择热液裂隙-脉系统和构造-蚀变-矿化网络为重点研究对象;通过几何学描述、运动学判断、流变学分析、动力学解析和热力学综合,厘定控矿构造格架,定位矿化中心,示踪成矿流体通道和多种矿化样式的增量生长过程及其关键控制,揭示渗透性结构的时-空演变规律及构造再活化与成矿定位的成因关联,建立构造-流体耦合成矿模式,服务新一轮战略找矿突破。以胶东焦家金矿田为例,开展控矿构造理论研究和成矿预测应用实践,证实了其科学性和有效性。 展开更多
关键词 热液裂隙-脉系统 构造-蚀变-矿化网络 渗透性结构与成矿定位 流体通道和矿床增量生长 构造-流体耦合成矿模式
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基于振动台试验的鱼线固定梅瓶文物响应规律性研究 被引量:1
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作者 杨维国 高雅巍 +3 位作者 王萌 刘佩 葛家琪 邹晓光 《振动与冲击》 EI CSCD 北大核心 2024年第4期250-260,共11页
为了探索鱼线固定梅瓶文物在实际博物馆的地震响应以及抗震效果,首先选取了典型梅瓶文物,并在三层钢筋混凝土框架结构中开展了24种地震工况的振动台试验,然后建立了上述试验所用梅瓶文物的有限元模型,验证了有限元模型的准确性,最后采... 为了探索鱼线固定梅瓶文物在实际博物馆的地震响应以及抗震效果,首先选取了典型梅瓶文物,并在三层钢筋混凝土框架结构中开展了24种地震工况的振动台试验,然后建立了上述试验所用梅瓶文物的有限元模型,验证了有限元模型的准确性,最后采用增量动力分析法分析了该文物在两种常见直径鱼线保护措施下的运动响应。结果表明:鱼线固定梅瓶文物在地震作用下会产生滑移、摇摆、倾覆以及鱼线断裂等现象;不同楼层下的文物响应差别较大,尤其在大震作用下,高楼层的鱼线固定梅瓶文物易发生倾覆和鱼线断裂破坏,要重视高楼层文物的震前保护措施;在较强的地震作用下,仅依靠增大鱼线直径有时对控制文物的倾覆情况起不到关键性决定作用,需要进一步采取其它措施对文物进行保护。 展开更多
关键词 鱼线固定梅瓶文物 振动台试验 有限元模型 运动响应 增量动力分析
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基于PSO-BP神经网络的分拣机器人视觉反馈跟踪 被引量:1
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作者 杨静宜 白向伟 《国外电子测量技术》 2024年第1期166-172,共7页
针对分拣机器人视觉反馈跟踪精度差、耗时较长的问题,研究基于粒子群算法-反向传播(particle swarm optimization-back propagation,PSO-BP)神经网络的分拣机器人视觉反馈跟踪方法,以提升视觉反馈跟踪效果。依据分拣机器人的视觉反馈信... 针对分拣机器人视觉反馈跟踪精度差、耗时较长的问题,研究基于粒子群算法-反向传播(particle swarm optimization-back propagation,PSO-BP)神经网络的分拣机器人视觉反馈跟踪方法,以提升视觉反馈跟踪效果。依据分拣机器人的视觉反馈信息,建立分拣机器人运动学模型,并求解分拣机器人机械臂输出位置和输入位置的误差函数;利用PSO算法优化BP神经网络的权值与偏置;在权值与偏置优化后的BP神经网络内,输入误差函数,预测分拣机器人视觉反馈跟踪控制量;利用预测视觉反馈跟踪控制量,在线调整增量式比例-积分-微分(proportional-integral-derivative,PID)的参数,输出高精度的分拣机器人视觉反馈跟踪控制量,实现分拣机器人视觉反馈跟踪。实验结果表明,该方法可有效视觉反馈跟踪分拣机器人机械臂的关节角;存在干扰情况下,在运行时间为10 s左右时,阶跃响应趋于稳定;有干扰情况下,视觉反馈跟踪的平均误差为0.09 cm,耗时平均值为0.10 ms;无干扰情况下,平均误差为0.03 cm,耗时平均值为0.04 ms。 展开更多
关键词 PSO-BP神经网络 分拣机器人 视觉反馈跟踪 运动学模型 误差函数 增量式PID
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考虑氯离子侵蚀的深层隧道地震易损性分析
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作者 管民生 张静 +1 位作者 李渊 陈湘生 《深圳大学学报(理工版)》 CAS CSCD 北大核心 2024年第6期720-729,I0009,共11页
氯离子侵蚀对隧道的抗震性能产生不利影响,研究隧道在侵蚀环境下的地震易损性对全寿命周期的抗震评估至关重要.为了量化分析隧道长期在氯离子侵蚀作用下抗震性能的退化趋势,基于地震易损性理论,结合考虑氯离子侵蚀影响的混凝土和钢筋强... 氯离子侵蚀对隧道的抗震性能产生不利影响,研究隧道在侵蚀环境下的地震易损性对全寿命周期的抗震评估至关重要.为了量化分析隧道长期在氯离子侵蚀作用下抗震性能的退化趋势,基于地震易损性理论,结合考虑氯离子侵蚀影响的混凝土和钢筋强度时变模型,分别选取峰值地面加速度和隧道直径变形率作为地震动强度指标和结构损伤指标,通过采用增量动力分析(incremental dynamic analysis,IDA)方法进行时程分析,深入探讨了深层隧道的地震易损性,得到了不同服役时间及不同损伤状态下的地震易损性曲线.结果表明:在相同的服役时间和地震动强度下,轻微损伤的发生概率最高,其次是中等和严重损伤;在相同的损伤状态和地震动强度下,随着服役时间的延长,氯离子侵蚀导致隧道抗震性能下降,损伤概率上升;在轻微损伤状态下,当峰值地面加速度为0.30g且服役达100 a时,损伤概率是服役初期的2.39倍.研究结果可为深层隧道的抗震设计提供科学依据. 展开更多
关键词 隧道工程 深层隧道 地震易损性 增量动力分析 氯离子侵蚀 时变模型
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书面双语驱动的渐进式微生物学双语教学模式探索与实践
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作者 晏磊 张爽 +2 位作者 王艳红 毕少杰 陈宁 《黑龙江水产》 2024年第5期652-656,共5页
微生物学作为生命科学学科专业领域重要的基础必修课程,是培养适应当前生物经济快速发展、生物制造迭代升级、生物新质生产力高质量发展创新人才的核心单元之一。全球化的发展和跨文化交流的增加,大大提高了微生物学课程中引入双语教学... 微生物学作为生命科学学科专业领域重要的基础必修课程,是培养适应当前生物经济快速发展、生物制造迭代升级、生物新质生产力高质量发展创新人才的核心单元之一。全球化的发展和跨文化交流的增加,大大提高了微生物学课程中引入双语教学的必要性。不同于口语双语,书面双语能力基本为各行业所需的,应用机会要大得多。文章从中国的现实出发,遵循采用外文原版教材原则,建立融入教学理念、教学目标、英文原版教材、多元化协同渐进式教学方式和形成性考核评价体系的“五位一体”渐进式微生物学双语教学模式。该模式在黑龙江八一农垦大学部分本科专业和硕士点进行了初步实践,取得了较好的效果。书面双语驱动的渐进式微生物学双语教学模式,淡化口语,让双语教学更加适应中国英语水平现状。 展开更多
关键词 书面双语 微生物学课程 教学模式 渐进式
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协同性三次分配:贫困治理视域下农民农村共同富裕的实现机制
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作者 武晋 祝云凤 《天津行政学院学报》 CSSCI 北大核心 2024年第4期76-86,共11页
在“后2020时代”,相对贫困治理与共同富裕场域交叠、逻辑同构、成效相承,二者具有一体推进的关系,共同服务于中国式现代化的伟大实践。贫困治理视域下,要推进农民农村共同富裕,关键是要破解城乡空间资源配置失衡之“困”所致的农村之... 在“后2020时代”,相对贫困治理与共同富裕场域交叠、逻辑同构、成效相承,二者具有一体推进的关系,共同服务于中国式现代化的伟大实践。贫困治理视域下,要推进农民农村共同富裕,关键是要破解城乡空间资源配置失衡之“困”所致的农村之“贫”。协同性三次分配机制作为一种关系创新,通过资源要素回流、地方市场建构、农民无差受惠的“三重奏”,为城乡资源要素连接与激活、动能输入与转化提供制度性通道,改变了农村低水平的要素自循环与贫困再生产。它是渐进平衡贫困治理模式下联动、协同、演化三大功能整合互动的可操作化机制,通过三种分配形式的制度合力保障了相对贫困治理以发展为内容导向、以共享为价值导向、以均衡为目标导向,可有力有效推进农民农村共同富裕。 展开更多
关键词 共同富裕 贫困治理 相对贫困 协同性三次分配 渐进平衡模式
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