The construction of centralized and standardized material databases is essential to support both scientific innovation and industrial application.However,for rare and precious metal materials,existing data resources a...The construction of centralized and standardized material databases is essential to support both scientific innovation and industrial application.However,for rare and precious metal materials,existing data resources are often decentralized.This results in persistent issues such as data silos and fragmentation,which significantly hinder efficient data utilization and collaboration.In response to these challenges,this study investigates the development of an integrated platform for sharing genetic data of rare and precious metal materials.The research begins by analyzing current trends in material data platforms,both domestically and internationally.These insights help inform the architectural design.The core of the platform consists of several key modules.Data resource integration is designed to aggregate and harmonize heterogeneous data from diverse sources.A structured data management system supports efficient storage and retrieval.A computational environment enables data analysis and modeling.A trusted sharing mechanism ensures security and access control.By integrating these functionalities,the platform aims to provide a unified ecosystem.This system facilitates open yet secure data exchange,promotes reproducibility,and enhances research efficiency.Finally,the article summarizes the initial implementation of the platform.It discusses its potential limitations and outlines future directions for development,including the integration of artificial intelligence tools and the expansion of data coverage.展开更多
Under the current background of an information society,the digital transformation of enterprises has become a necessary means to enhance the competitiveness of enterprises.This article is based on the industrial Inter...Under the current background of an information society,the digital transformation of enterprises has become a necessary means to enhance the competitiveness of enterprises.This article is based on the industrial Internet platform,the digital planning and architecture of enterprises research.First,we analyze the current challenges of digital transformation and the development opportunities brought by the industrial Internet.Then,we propose a digital planning method based on the industrial Internet platform,which takes the full connectivity of people,machine and things and intelligent decision making as the core,takes data collection,processing,analysis and application as the main line,and finally forms the top-level design of the digital transformation of enterprises.At the same time,we also built an industrial Internet platform architecture model,including the previous end perception layer,network transmission layer,platform service layer,and application innovation layer for four levels,to support enterprises in innovative applications and decision support under the industrial Internet environment.Research shows that this kind of enterprise digital planning and architecture based on an industrial Internet platform can effectively promote enterprises to achieve business model innovation,system innovation,and strengthen the flexibility and agility of enterprises to respond to market changes.The results of this research not only have important theoretical and practical significance for guiding enterprises to carry out digital planning and build an industrial Internet platform,but also provide useful reference for relevant policy formulation.展开更多
We are sorry for the mistakes of Affiliation,"a State Key Laboratory of Advanced Fiber Materials,Center for Advanced Low-Dimension Materials,Donghua University,Shanghai 201620,China"should be replaced by&quo...We are sorry for the mistakes of Affiliation,"a State Key Laboratory of Advanced Fiber Materials,Center for Advanced Low-Dimension Materials,Donghua University,Shanghai 201620,China"should be replaced by"a State Key Laboratory of Advanced Fiber Materials,Center for Advanced Low-Dimension Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620,China".We apologized for the inconvenience caused by this error.展开更多
In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasib...In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasibility and key implementing technology of the model are expatiated. A prototype system is implemented to validate it.展开更多
The pattern of dendritic growth and distortion of dendritic network in the platform have been investigated by one mold casting with different platform length during directional solidification. As the platform length e...The pattern of dendritic growth and distortion of dendritic network in the platform have been investigated by one mold casting with different platform length during directional solidification. As the platform length elongates, the symmetry of dendritic growth along left and right edges gradually worsens in platform base. While the platform length reaches 14 mm, the distortion of dendritic network is first observed in outward platform. It is found that the distortion of dendritic network along platform inside is more serious than that along platform edges. Both [001] deviation and accumulated misorientation along platform inside, up to 9~ and 16.3~, respectively, are far greeter than those along left-outward-right edges. The deformation of dendritic network in a platform may be caused by the asymmetry of the solidification front at the mush zone.展开更多
The micromation and precision of the Micro-Electromechanical System demand that its manufacturing, measuring and assembling must work in a micro-manufacturing platform with good ability to isolate vibrations. This pap...The micromation and precision of the Micro-Electromechanical System demand that its manufacturing, measuring and assembling must work in a micro-manufacturing platform with good ability to isolate vibrations. This paper develops a vibration isolation system of micro-manufacturing platform. The brains of many kinds of birds can isolate vibrations well, such as woodpecker’s brain. When a woodpecker pecks the wood at the speed as 1.6 times as the velocity of sound, its brain will tolerate the wallop 1 500 times of the weight of itself without any damage. The isolation mechanics and organic texture of woodpecker’s brain that has good isolation characteristics were studied. A structure model of vibration isolation system for the micro-manufacturing platform is established based on the bionics of the bird’s brain vibration isolation mechanism. In order to isolate effectively the high frequency vibrations from the ground, a rubber layer is used to isolate vibrations passively between the micro-manufacturing platform’s pedestal and the ground. This layer corresponds to the cartilage and muscles in the outer meninges of the bird’s brain. The active vibration isolation technique is adopted to isolate vibrations between the micro-manufacturing platform and the pedestal. Air springs are used as elastic components, which correspond to the interspaces between the outer meninges and the encephala of the bird’s brain. Actuators are made of giant magnetostrictive material, and it corresponds to the nerves and neural muscles linking the meninges and the encephala. The actuators and air springs are arranged vertically in parallel to make use of the giant magnetostrictive actuators effectively. The air springs support almost all weight of the micro-manufacturing platform and the giant magnetostrictive actuators support almost no weight. In order to realize high performance to isolate complex micro-vibration, the control method using a three-layer neural network is presented. This vibration control system takes into account the floor disturbance and the direct disturbance acting on the micro-manufacturing platform. The absolute acceleration of the micro-manufacturing platform is used as the performance index of vibration control. The performance of the control system is tested by numerical simulation. Simulation results show that the active vibration isolation system has good isolation performance against the floor disturbance and the direct disturbance acting on the micro-manufacturing platform in all the frequency range.展开更多
In the present work, damage detection for offshore platforms is divided into three steps. Firstly, the located direction of the damaged member is detemfined by the pmbabilistic neural network with input of the change ...In the present work, damage detection for offshore platforms is divided into three steps. Firstly, the located direction of the damaged member is detemfined by the pmbabilistic neural network with input of the change rate of normalized medal frequency. Secondly, the profile and layer of the damaged member is also determined by the pmbabilistic neural network with input of the normalized damage-signal index. Finally, the damage extent is determined by the back propagation neural networks with input of the squared change rate of modal frequency. So the size of the network and the training time can be reduced greatly. All these networks are trained with simulated data obtained from the finite element model of an experiment model. Then these trained neural networks are examined with data obtained from impulse tests on the experiment model. The experiment results show that the trained neural networks are able to detect the damaged member with reasonable accuracy.展开更多
A new active control scheme, based on neural network, for the suppression of oscillation in multiple-degree-of-freedom (MDOF) offshore platforms, is studied in this paper. With the main advantages of neural network, i...A new active control scheme, based on neural network, for the suppression of oscillation in multiple-degree-of-freedom (MDOF) offshore platforms, is studied in this paper. With the main advantages of neural network, i.e. the inherent robustness, fault tolerance, and generalized capability of its parallel massive interconnection structure, the active structural control of offshore platforms under random waves is accomplished by use of the BP neural network model. The neural network is trained offline with the data generated from numerical analysis, and it simulates the process of Classical Linear Quadratic Regular Control for the platform under random waves. After the learning phase, the trained network has learned about the nonlinear dynamic behavior of the active control system, and is capable of predicting the active control forces of the next time steps. The results obtained show that the active control is feasible and effective, and it finally overcomes time delay owing to the robustness, fault tolerance, and generalized capability of artificial neural network.展开更多
Phosphorite has become increasingly important as the raw material for phosphatic fertilizer. Phosphorite nodules are widespread in the Kursk complex deposit (Russian platform). Genesis of these nodules has long been a...Phosphorite has become increasingly important as the raw material for phosphatic fertilizer. Phosphorite nodules are widespread in the Kursk complex deposit (Russian platform). Genesis of these nodules has long been a matter of debate, and this has hampered understanding of the mechanism and controls in the formation of the nodules. In this paper, we report the petrographical, mineralogical, and geochemical data of the Lebedinsky phosphorite nodules. Petrographic study reveals complex phosphatic cement resulting in the replacement of apatite minerals around quartz grains. The main mineral composition consists of quartz, phosphate minerals (apatite, francolite mainly), feldspar, iron hydroxides and carbonate minerals. These results, when combined with available data, are used to address the origin of the phosphorite nodules. The nodules are characterized by the universal presence of biogenic and chemical signatures which is phosphorus crown around crystal grains. The structure of the nodules is massive. Their texture is depicted by basaltic cement and concretion, which consists mainly of apatite and its varieties, with general formula: Ca_10 (PO_4, CO_3) 6(F,OH,Cl). Variation of mineralogy appears dependent on geological setting. Microscopic observations of biogenic fossils in Lebedinsky phosphorite favor a chemical and biogenic origin of phosphorites. Weathering has been suggested to be capable of liberating as much as 20 %-35 % P_2O_5 from sedimentary rocks. Previous investigations demonstrate that weathering of the Proterozoic substratum was the main cause in the formation of Fe, Mo, Mn, Pb, Zn, and P in the Russian platform. We therefore suggest that both weathering and biochemical processes have been positive in the formation of the Lebedinsky phosporite nodules. However, whether continental weathering or oceanic bio-chemical processes are more relevant in the phosphorite accumulation remains undetermined.展开更多
The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is propose...The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.展开更多
To take advantage of the abundance of both fishery and wave energy resources in offshore sea areas,a novel floating platform with a heaving buoy-based wave energy converter(WEC)assembled with a set of net cages is pre...To take advantage of the abundance of both fishery and wave energy resources in offshore sea areas,a novel floating platform with a heaving buoy-based wave energy converter(WEC)assembled with a set of net cages is presented in this work.The floating WEC system provides a power supply,while the net cages are used for aquaculture.It is designed to have an independent and self-operation breeding function.An experimental study is carried out to investigate the hydrodynamic performance of the device in a wave tank considering the factors of net cages,draft depth,and power take-off,and results show that these variables have significant effects on wave energy capture.Incident waves with short periods cause intense interactions that allow the device to undergo large relative motion.The draft depth could be determined according to wave period rather than wave height.This study also explores the response amplitude operator of the device and determines its resonance scope.The experimental results could provide reliable information for future studies on phase differences and the design of two-body WECs.展开更多
In order to facilitate optimal quality and continuity of care and self-management of patients with schizophrenia, Personal Control in Rehabilitation (PCR) has been developed, a comprehensive internet-based platform. P...In order to facilitate optimal quality and continuity of care and self-management of patients with schizophrenia, Personal Control in Rehabilitation (PCR) has been developed, a comprehensive internet-based platform. PCR aims to reach patients with schizophrenia or related psychotic disorders and their (in)formal caregivers. It provides caregivers and patients with a kind of dashboard giving them (tailored) information about the physical and psychosocial situation of the patient, their compliance with treatment, and facilitates optimal self-management for patients. With the use of PCR, informal caregivers have access to information about treatment and can consult formal caregivers, formal caregivers have easy access to the multidisciplinary guideline schizophrenia and to the regional care plans. Patients and their formal and informal caregivers completed questionnaires about empowerment, quality of life, quality of care and workload before the introduction of PCR and nine months later. A sample of them also participates in focus group discussions about the usefulness and usability of PCR and bottle necks in using the platform. Response to the questionnaires, especially at followup, was not adequate for statistical analyses of its results. Therefore, the focus of this paper is on the process evaluation of the implementation of PCR in two large mental health organisations in the Netherlands. Data for this evaluation are results of a number of open questions of the questionnaire and results of the focus group discussions. In these discussions, 19 patients, 12 informal caregivers, 33 formal caregivers and three managers participated. Preliminary results of this study show that the implementation of PCR is feasible and patients, formal and informal caregivers were satisfied with the use of PCR and frequently used PCR to communicate, make appointments, give feedback and look for information about their disease and its treatment. PCR is considered as a help in reaching more self-management by patients, to facilitate communication between patients and caregivers, and to match treatment and support. It seems useful also for other patient groups and their (in)formal caregivers like patients with depression, autism and addiction disorders.展开更多
The development of Internet technology has brought convenience to the development of education and teaching,and has also changed the traditional methods and means of education and teaching. The construction of an inte...The development of Internet technology has brought convenience to the development of education and teaching,and has also changed the traditional methods and means of education and teaching. The construction of an integrated network teaching platform based on Internet technology brings new opportunities for the development of higher education. Taking the construction of the integrated network teaching platform of Northwest A&F University as an example,the current situation and existing problems in the construction of the integrated network teaching platform of the Northwest A&F University are explained. By proposing the promotion strategies for the application of the integrated network teaching platform,the construction of the integrated network teaching platform is improved,thereby facilitating the online and offline mixed teaching and further promoting the improvement of teaching level and teaching effect.展开更多
Rapeseed(Brassica napus)is an oil crop grown worldwide,making it a key plant species in molecular breeding research.However,the complexity of its polyploid genome increases sequencing costs and reduces sequencing accu...Rapeseed(Brassica napus)is an oil crop grown worldwide,making it a key plant species in molecular breeding research.However,the complexity of its polyploid genome increases sequencing costs and reduces sequencing accuracy.Target capture coupled with high-throughput sequencing is an efficient approach for detecting genetic variation at genomic regions or loci of interest.In this study,588 resequenced accessions of rapeseed were used to develop a target capture sequencing SNP genotyping platform named BnaPan50T.The platform comprised 54,765,with 54,058 resequenced markers from the pan-genome,and 855 variant trait-associated markers for 12 agronomic traits.The capture quality of BnaPan50T was demonstrated well in 12 typical accessions.Compared with a conventional genotyping array,BnaPan50T has a high SNP density and a high proportion of SNPs in unique physical positions and in annotated functional genes,promising wide application.Target capture sequencing and wholegenome resequencing in 90 doubled-haploid lines yielded 60%specificity,78%uniformity within tenfold coverage range,and 93%genotyping accuracy for the platform.BnaPan50T was used to construct a genetic map for quantitative trait loci(QTL)mapping,identify 21 unique QTL,and predict several candidate genes for yield-related traits in multiple environments.A set of 132 core SNP loci was selected from BnaPan50T to construct DNA fingerprints and germplasm identification resources.This study provides genomics resources to support target capture sequencing,genetic analysis and genomic breeding of rapeseed.展开更多
In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active...In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active control strategy is established. A back propagation artificial neural network (ANN) is used to adjust the orifice opening of TLCD because of the nonlinear motion of liquid in TLCD. The effectiveness of the control method is verified by numerical examples.展开更多
Forward osmosis(FO), as an emerging technology, is influenced by different factors such as operating conditions,module characteristics, and membrane properties. The general aim of this study was to develop a suitable(...Forward osmosis(FO), as an emerging technology, is influenced by different factors such as operating conditions,module characteristics, and membrane properties. The general aim of this study was to develop a suitable(flexible,comprehensive, and convenient to use) computational tool which is able to simulate osmosis through an asymmetric membrane oriented in pressure retarded osmosis(PRO) mode in a wide variety of scenarios. For this purpose, an agent-based model was created in NetLogo platform, which is an easy-to-use application environment with graphical visualization abilities and well suited for modeling a complex system evolving over time. The simulation results were validated with empirical data obtained from literature and a great agreement was observed. The effect of various parameters on process performance was investigated in terms of temperature,cross-flow velocity, length of the module, pure water permeability coefficient, and structural parameter of the membrane. Results demonstrated that the increase in all parameters, except structural parameter of the membrane and the length of module led to the increase of average water flux. Moreover, nine different draw solutes were selected in order to assess the influence of net bulk osmotic pressure difference between the draw solution(DS) and feed solution(FS)(known as the driving force of FO process) on water flux. Based on the findings of this paper, the performance of FO process(PRO mode) can be efficiently evaluated using the NetL ogo platform.展开更多
The offshore jacket platform is a complex and time-varying nonlinear system, which can be excited of harmful vibration by external loads. It is difficult to obtain an ideal control performance for passive control meth...The offshore jacket platform is a complex and time-varying nonlinear system, which can be excited of harmful vibration by external loads. It is difficult to obtain an ideal control performance for passive control methods or traditional active control methods based on accurate mathematic model. In this paper, an adaptive inverse control method is proposed on the basis of novel rough neural networks （RNN） to control the harmful vibration of the offshore jacket platform, and the offshore jacket platform model is established by dynamic stiffness matrix （DSM） method. Benefited from the nonlinear processing ability of the neural networks and data interpretation ability of the rough set theory, RNN is utilized to identify the predictive inverse model of the offshore jacket platform system. Then the identified model is used as the adaptive predictive inverse controller to control the harmful vibration caused by wave and wind loads, and to deal with the delay problem caused by signal transmission in the control process. The numerical results show that the constructed novel RNN has advantages such as clear structure, fast training speed and strong error-tolerance ability, and the proposed method based on RNN can effectively control the harmful vibration of the offshore jacket platform.展开更多
Magnetic susceptibility(MS)data were obtained from 11 sections of the Doushantuo(Edicaran)cap carbonate that directly overlies the Nantuo glacial diamictite in the southeastern margin of the Yangtze plat-form.The MS d...Magnetic susceptibility(MS)data were obtained from 11 sections of the Doushantuo(Edicaran)cap carbonate that directly overlies the Nantuo glacial diamictite in the southeastern margin of the Yangtze plat-form.The MS data revealed two regionally correlatable peaks at the bottom and top of the cap carbonate,sepa-rated by an interval of low values.The lower MS peak coincides with high percentage of insoluble siliciclastic residues that are compositionally identical to the matrix of the underlying diamictite,suggesting its origin con-trolled mainly by detrital components during the first phase of cap carbonate deposition at the end of the glacia-tion.The upper MS peak is associated with high clay content and iron sulfides,and can be interpreted as either derived from enhanced greenhouse weathering that could have brought more terrigenous components into the ocean,or the result of ocean anoxia at the late stage of cap carbonate deposition that could led to formation of abundant iron sulfides.The regionally consistent MS curves from the cap carbonates provided the first geo-physical record for the rapid climate change from icehouse to greenhouse conditions in the aftermath of the Neoproterozoic“snowball Earth”event.展开更多
基金funded by the Major Science and Technology Projects in Yunnan Province(202502AD080002)Yunnan Fundamental Research Projects(202201AT070161)Yunnan Province High-Level Talent Introduction Program(C619300A023).
文摘The construction of centralized and standardized material databases is essential to support both scientific innovation and industrial application.However,for rare and precious metal materials,existing data resources are often decentralized.This results in persistent issues such as data silos and fragmentation,which significantly hinder efficient data utilization and collaboration.In response to these challenges,this study investigates the development of an integrated platform for sharing genetic data of rare and precious metal materials.The research begins by analyzing current trends in material data platforms,both domestically and internationally.These insights help inform the architectural design.The core of the platform consists of several key modules.Data resource integration is designed to aggregate and harmonize heterogeneous data from diverse sources.A structured data management system supports efficient storage and retrieval.A computational environment enables data analysis and modeling.A trusted sharing mechanism ensures security and access control.By integrating these functionalities,the platform aims to provide a unified ecosystem.This system facilitates open yet secure data exchange,promotes reproducibility,and enhances research efficiency.Finally,the article summarizes the initial implementation of the platform.It discusses its potential limitations and outlines future directions for development,including the integration of artificial intelligence tools and the expansion of data coverage.
文摘Under the current background of an information society,the digital transformation of enterprises has become a necessary means to enhance the competitiveness of enterprises.This article is based on the industrial Internet platform,the digital planning and architecture of enterprises research.First,we analyze the current challenges of digital transformation and the development opportunities brought by the industrial Internet.Then,we propose a digital planning method based on the industrial Internet platform,which takes the full connectivity of people,machine and things and intelligent decision making as the core,takes data collection,processing,analysis and application as the main line,and finally forms the top-level design of the digital transformation of enterprises.At the same time,we also built an industrial Internet platform architecture model,including the previous end perception layer,network transmission layer,platform service layer,and application innovation layer for four levels,to support enterprises in innovative applications and decision support under the industrial Internet environment.Research shows that this kind of enterprise digital planning and architecture based on an industrial Internet platform can effectively promote enterprises to achieve business model innovation,system innovation,and strengthen the flexibility and agility of enterprises to respond to market changes.The results of this research not only have important theoretical and practical significance for guiding enterprises to carry out digital planning and build an industrial Internet platform,but also provide useful reference for relevant policy formulation.
文摘We are sorry for the mistakes of Affiliation,"a State Key Laboratory of Advanced Fiber Materials,Center for Advanced Low-Dimension Materials,Donghua University,Shanghai 201620,China"should be replaced by"a State Key Laboratory of Advanced Fiber Materials,Center for Advanced Low-Dimension Materials,College of Materials Science and Engineering,Donghua University,Shanghai 201620,China".We apologized for the inconvenience caused by this error.
文摘In order to manage all kinds of network security devices and software systems efficiently, and make them collaborate with each other, the model for an open network security management platform is presented. The feasibility and key implementing technology of the model are expatiated. A prototype system is implemented to validate it.
基金supported by the National Basic Research Program of China (Grant No. 2010CB631206)the National Natural Science Foundation of China (Grant Nos. 51271186, U1037601, 50931004, 51204156 and 51101153)the Program of "One Hundred Talented People" of the Chinese Academy of Sciences
文摘The pattern of dendritic growth and distortion of dendritic network in the platform have been investigated by one mold casting with different platform length during directional solidification. As the platform length elongates, the symmetry of dendritic growth along left and right edges gradually worsens in platform base. While the platform length reaches 14 mm, the distortion of dendritic network is first observed in outward platform. It is found that the distortion of dendritic network along platform inside is more serious than that along platform edges. Both [001] deviation and accumulated misorientation along platform inside, up to 9~ and 16.3~, respectively, are far greeter than those along left-outward-right edges. The deformation of dendritic network in a platform may be caused by the asymmetry of the solidification front at the mush zone.
文摘The micromation and precision of the Micro-Electromechanical System demand that its manufacturing, measuring and assembling must work in a micro-manufacturing platform with good ability to isolate vibrations. This paper develops a vibration isolation system of micro-manufacturing platform. The brains of many kinds of birds can isolate vibrations well, such as woodpecker’s brain. When a woodpecker pecks the wood at the speed as 1.6 times as the velocity of sound, its brain will tolerate the wallop 1 500 times of the weight of itself without any damage. The isolation mechanics and organic texture of woodpecker’s brain that has good isolation characteristics were studied. A structure model of vibration isolation system for the micro-manufacturing platform is established based on the bionics of the bird’s brain vibration isolation mechanism. In order to isolate effectively the high frequency vibrations from the ground, a rubber layer is used to isolate vibrations passively between the micro-manufacturing platform’s pedestal and the ground. This layer corresponds to the cartilage and muscles in the outer meninges of the bird’s brain. The active vibration isolation technique is adopted to isolate vibrations between the micro-manufacturing platform and the pedestal. Air springs are used as elastic components, which correspond to the interspaces between the outer meninges and the encephala of the bird’s brain. Actuators are made of giant magnetostrictive material, and it corresponds to the nerves and neural muscles linking the meninges and the encephala. The actuators and air springs are arranged vertically in parallel to make use of the giant magnetostrictive actuators effectively. The air springs support almost all weight of the micro-manufacturing platform and the giant magnetostrictive actuators support almost no weight. In order to realize high performance to isolate complex micro-vibration, the control method using a three-layer neural network is presented. This vibration control system takes into account the floor disturbance and the direct disturbance acting on the micro-manufacturing platform. The absolute acceleration of the micro-manufacturing platform is used as the performance index of vibration control. The performance of the control system is tested by numerical simulation. Simulation results show that the active vibration isolation system has good isolation performance against the floor disturbance and the direct disturbance acting on the micro-manufacturing platform in all the frequency range.
基金The project was financially supported by the National Natural Science Foundation of China (Grant No.50479027)and by the Natural Science Foundation of Qingdao (Grant No.05-2-JC-88)
文摘In the present work, damage detection for offshore platforms is divided into three steps. Firstly, the located direction of the damaged member is detemfined by the pmbabilistic neural network with input of the change rate of normalized medal frequency. Secondly, the profile and layer of the damaged member is also determined by the pmbabilistic neural network with input of the normalized damage-signal index. Finally, the damage extent is determined by the back propagation neural networks with input of the squared change rate of modal frequency. So the size of the network and the training time can be reduced greatly. All these networks are trained with simulated data obtained from the finite element model of an experiment model. Then these trained neural networks are examined with data obtained from impulse tests on the experiment model. The experiment results show that the trained neural networks are able to detect the damaged member with reasonable accuracy.
文摘A new active control scheme, based on neural network, for the suppression of oscillation in multiple-degree-of-freedom (MDOF) offshore platforms, is studied in this paper. With the main advantages of neural network, i.e. the inherent robustness, fault tolerance, and generalized capability of its parallel massive interconnection structure, the active structural control of offshore platforms under random waves is accomplished by use of the BP neural network model. The neural network is trained offline with the data generated from numerical analysis, and it simulates the process of Classical Linear Quadratic Regular Control for the platform under random waves. After the learning phase, the trained network has learned about the nonlinear dynamic behavior of the active control system, and is capable of predicting the active control forces of the next time steps. The results obtained show that the active control is feasible and effective, and it finally overcomes time delay owing to the robustness, fault tolerance, and generalized capability of artificial neural network.
文摘Phosphorite has become increasingly important as the raw material for phosphatic fertilizer. Phosphorite nodules are widespread in the Kursk complex deposit (Russian platform). Genesis of these nodules has long been a matter of debate, and this has hampered understanding of the mechanism and controls in the formation of the nodules. In this paper, we report the petrographical, mineralogical, and geochemical data of the Lebedinsky phosphorite nodules. Petrographic study reveals complex phosphatic cement resulting in the replacement of apatite minerals around quartz grains. The main mineral composition consists of quartz, phosphate minerals (apatite, francolite mainly), feldspar, iron hydroxides and carbonate minerals. These results, when combined with available data, are used to address the origin of the phosphorite nodules. The nodules are characterized by the universal presence of biogenic and chemical signatures which is phosphorus crown around crystal grains. The structure of the nodules is massive. Their texture is depicted by basaltic cement and concretion, which consists mainly of apatite and its varieties, with general formula: Ca_10 (PO_4, CO_3) 6(F,OH,Cl). Variation of mineralogy appears dependent on geological setting. Microscopic observations of biogenic fossils in Lebedinsky phosphorite favor a chemical and biogenic origin of phosphorites. Weathering has been suggested to be capable of liberating as much as 20 %-35 % P_2O_5 from sedimentary rocks. Previous investigations demonstrate that weathering of the Proterozoic substratum was the main cause in the formation of Fe, Mo, Mn, Pb, Zn, and P in the Russian platform. We therefore suggest that both weathering and biochemical processes have been positive in the formation of the Lebedinsky phosporite nodules. However, whether continental weathering or oceanic bio-chemical processes are more relevant in the phosphorite accumulation remains undetermined.
基金financially supported by the Postgraduate Research & Practice Innovation Program of Jiangsu Province(Grant No.KYCX18_2311)
文摘The mechanisms of soil structure interaction have drawn much attention in the past years in the installation and operation of jack-up platform. A bionic spudcan produced by biomimetic of egg and snail shell is proposed, and the performance of the penetration and extraction are analyzed by numerical method. The geometric contour of egg and snail shell is measured, and its mathematical model is established respectively. According to the structure of existing spudcan of jack-up platform, three kinds of typical biomimetic spudcan are designed. Furthermore, numerical analysis models of biomimetic spudcan are established respectively to study the soil structure interaction mechanism in the process of penetration and extraction, and contrastive analysis of resistance characteristics are carried out. To conclude, the results show that the biomimetic spudcan facilitates the platform installation, and it is also beneficial to the improvement of the bearing capacity of spudcan.
基金financially supported by the Special Project for Marine Renewable Energy (No. GHME2016YY02)the National Key R&D Program of China (No. 2018YFB 1501900)+1 种基金the Shandong Provincial Natural Science Key Basic Program (No. ZR2017ZA0202)the Qingdao Municipal Science & Technology Program (No. 15-8-3-7jch)
文摘To take advantage of the abundance of both fishery and wave energy resources in offshore sea areas,a novel floating platform with a heaving buoy-based wave energy converter(WEC)assembled with a set of net cages is presented in this work.The floating WEC system provides a power supply,while the net cages are used for aquaculture.It is designed to have an independent and self-operation breeding function.An experimental study is carried out to investigate the hydrodynamic performance of the device in a wave tank considering the factors of net cages,draft depth,and power take-off,and results show that these variables have significant effects on wave energy capture.Incident waves with short periods cause intense interactions that allow the device to undergo large relative motion.The draft depth could be determined according to wave period rather than wave height.This study also explores the response amplitude operator of the device and determines its resonance scope.The experimental results could provide reliable information for future studies on phase differences and the design of two-body WECs.
文摘In order to facilitate optimal quality and continuity of care and self-management of patients with schizophrenia, Personal Control in Rehabilitation (PCR) has been developed, a comprehensive internet-based platform. PCR aims to reach patients with schizophrenia or related psychotic disorders and their (in)formal caregivers. It provides caregivers and patients with a kind of dashboard giving them (tailored) information about the physical and psychosocial situation of the patient, their compliance with treatment, and facilitates optimal self-management for patients. With the use of PCR, informal caregivers have access to information about treatment and can consult formal caregivers, formal caregivers have easy access to the multidisciplinary guideline schizophrenia and to the regional care plans. Patients and their formal and informal caregivers completed questionnaires about empowerment, quality of life, quality of care and workload before the introduction of PCR and nine months later. A sample of them also participates in focus group discussions about the usefulness and usability of PCR and bottle necks in using the platform. Response to the questionnaires, especially at followup, was not adequate for statistical analyses of its results. Therefore, the focus of this paper is on the process evaluation of the implementation of PCR in two large mental health organisations in the Netherlands. Data for this evaluation are results of a number of open questions of the questionnaire and results of the focus group discussions. In these discussions, 19 patients, 12 informal caregivers, 33 formal caregivers and three managers participated. Preliminary results of this study show that the implementation of PCR is feasible and patients, formal and informal caregivers were satisfied with the use of PCR and frequently used PCR to communicate, make appointments, give feedback and look for information about their disease and its treatment. PCR is considered as a help in reaching more self-management by patients, to facilitate communication between patients and caregivers, and to match treatment and support. It seems useful also for other patient groups and their (in)formal caregivers like patients with depression, autism and addiction disorders.
文摘The development of Internet technology has brought convenience to the development of education and teaching,and has also changed the traditional methods and means of education and teaching. The construction of an integrated network teaching platform based on Internet technology brings new opportunities for the development of higher education. Taking the construction of the integrated network teaching platform of Northwest A&F University as an example,the current situation and existing problems in the construction of the integrated network teaching platform of the Northwest A&F University are explained. By proposing the promotion strategies for the application of the integrated network teaching platform,the construction of the integrated network teaching platform is improved,thereby facilitating the online and offline mixed teaching and further promoting the improvement of teaching level and teaching effect.
基金supported by the National Natural Science Foundation of China(31871653 to K.L.,31830067 to J.L.)the Talent Project of Chongqing Natural Science Foundation(cstc2021ycjhbgzxm0033 to K.L.)Germplasm Creation Special Program of Southwest University.
文摘Rapeseed(Brassica napus)is an oil crop grown worldwide,making it a key plant species in molecular breeding research.However,the complexity of its polyploid genome increases sequencing costs and reduces sequencing accuracy.Target capture coupled with high-throughput sequencing is an efficient approach for detecting genetic variation at genomic regions or loci of interest.In this study,588 resequenced accessions of rapeseed were used to develop a target capture sequencing SNP genotyping platform named BnaPan50T.The platform comprised 54,765,with 54,058 resequenced markers from the pan-genome,and 855 variant trait-associated markers for 12 agronomic traits.The capture quality of BnaPan50T was demonstrated well in 12 typical accessions.Compared with a conventional genotyping array,BnaPan50T has a high SNP density and a high proportion of SNPs in unique physical positions and in annotated functional genes,promising wide application.Target capture sequencing and wholegenome resequencing in 90 doubled-haploid lines yielded 60%specificity,78%uniformity within tenfold coverage range,and 93%genotyping accuracy for the platform.BnaPan50T was used to construct a genetic map for quantitative trait loci(QTL)mapping,identify 21 unique QTL,and predict several candidate genes for yield-related traits in multiple environments.A set of 132 core SNP loci was selected from BnaPan50T to construct DNA fingerprints and germplasm identification resources.This study provides genomics resources to support target capture sequencing,genetic analysis and genomic breeding of rapeseed.
文摘In this paper, the control method for fixed offshore platforms using semi-active tuned liquid column damper (TLCD) is presented. The equation of motion for the platform-TLCD control system is given and the semi-active control strategy is established. A back propagation artificial neural network (ANN) is used to adjust the orifice opening of TLCD because of the nonlinear motion of liquid in TLCD. The effectiveness of the control method is verified by numerical examples.
文摘Forward osmosis(FO), as an emerging technology, is influenced by different factors such as operating conditions,module characteristics, and membrane properties. The general aim of this study was to develop a suitable(flexible,comprehensive, and convenient to use) computational tool which is able to simulate osmosis through an asymmetric membrane oriented in pressure retarded osmosis(PRO) mode in a wide variety of scenarios. For this purpose, an agent-based model was created in NetLogo platform, which is an easy-to-use application environment with graphical visualization abilities and well suited for modeling a complex system evolving over time. The simulation results were validated with empirical data obtained from literature and a great agreement was observed. The effect of various parameters on process performance was investigated in terms of temperature,cross-flow velocity, length of the module, pure water permeability coefficient, and structural parameter of the membrane. Results demonstrated that the increase in all parameters, except structural parameter of the membrane and the length of module led to the increase of average water flux. Moreover, nine different draw solutes were selected in order to assess the influence of net bulk osmotic pressure difference between the draw solution(DS) and feed solution(FS)(known as the driving force of FO process) on water flux. Based on the findings of this paper, the performance of FO process(PRO mode) can be efficiently evaluated using the NetL ogo platform.
文摘The offshore jacket platform is a complex and time-varying nonlinear system, which can be excited of harmful vibration by external loads. It is difficult to obtain an ideal control performance for passive control methods or traditional active control methods based on accurate mathematic model. In this paper, an adaptive inverse control method is proposed on the basis of novel rough neural networks （RNN） to control the harmful vibration of the offshore jacket platform, and the offshore jacket platform model is established by dynamic stiffness matrix （DSM） method. Benefited from the nonlinear processing ability of the neural networks and data interpretation ability of the rough set theory, RNN is utilized to identify the predictive inverse model of the offshore jacket platform system. Then the identified model is used as the adaptive predictive inverse controller to control the harmful vibration caused by wave and wind loads, and to deal with the delay problem caused by signal transmission in the control process. The numerical results show that the constructed novel RNN has advantages such as clear structure, fast training speed and strong error-tolerance ability, and the proposed method based on RNN can effectively control the harmful vibration of the offshore jacket platform.
基金This work was supported by the National Natural Science Foundation(Grant No.40032010B)
文摘Magnetic susceptibility(MS)data were obtained from 11 sections of the Doushantuo(Edicaran)cap carbonate that directly overlies the Nantuo glacial diamictite in the southeastern margin of the Yangtze plat-form.The MS data revealed two regionally correlatable peaks at the bottom and top of the cap carbonate,sepa-rated by an interval of low values.The lower MS peak coincides with high percentage of insoluble siliciclastic residues that are compositionally identical to the matrix of the underlying diamictite,suggesting its origin con-trolled mainly by detrital components during the first phase of cap carbonate deposition at the end of the glacia-tion.The upper MS peak is associated with high clay content and iron sulfides,and can be interpreted as either derived from enhanced greenhouse weathering that could have brought more terrigenous components into the ocean,or the result of ocean anoxia at the late stage of cap carbonate deposition that could led to formation of abundant iron sulfides.The regionally consistent MS curves from the cap carbonates provided the first geo-physical record for the rapid climate change from icehouse to greenhouse conditions in the aftermath of the Neoproterozoic“snowball Earth”event.
