Aims and scope Journal of Systems Engineering and Electronics,keeping abreast with the development trend of science and technology worldwide,reports the latest developments and achievements in both theoretical and pra...Aims and scope Journal of Systems Engineering and Electronics,keeping abreast with the development trend of science and technology worldwide,reports the latest developments and achievements in both theoretical and practical aspects of systems engineering,electronics and related research areas.The journal welcomes high quality original papers from a wide range of countries.The scope of the journal includes systems engineering,military systems,electronic technology,defense electronic technology,control theory and practice,software algorithm and simulation,reliability,computer development and application,and other topics in all related fields.展开更多
An analysis is made of the problem of sound radiation from infinite one-dimensional plateson elastic foundation, when the plates are subjected to the action of harmonic line forces movingat subsonic speeds (M 【 1). T...An analysis is made of the problem of sound radiation from infinite one-dimensional plateson elastic foundation, when the plates are subjected to the action of harmonic line forces movingat subsonic speeds (M 【 1). The expressions of nondimensional sound power are formulated andthe asymptotic forms of sound power in the low frequency regions are derived. The radiatedsound power is shown as a function of the stiffness of elastic foundation, in terms of stiffness fac-torψ, the moving speed of line force, in terms of Math number M, and the frequency, in termsof wavenumber ratio γ . The effects of the parameter ψ in conjunction with the parameters Mand γ on the radiated sound power level and the phenomenon of coincidence radiation are alsoinvestigated in detail.展开更多
In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of v...In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.展开更多
This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area rec...This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.展开更多
Diagrams as a visual technique played a key role in early modern natural history.Robert Morison,a Scottish botanist and the first Professor of Botany at Oxford University,made a noteworthy early attempt in the 17th ce...Diagrams as a visual technique played a key role in early modern natural history.Robert Morison,a Scottish botanist and the first Professor of Botany at Oxford University,made a noteworthy early attempt in the 17th century to promote the use of diagrams in plant taxonomy.By pioneering the use of diagrams as the core of his botanical monographs,Morison inverted the order in which text and diagrams are read in natural history books and made diagrams more than a mere adjunct to the main text.Morison also consciously aligned the structure of the diagrams with the spatial arrangement of his seed collection and the Oxford Botanic Garden,so that the diagrams functioned productively as a means of bridging difierent botanical practices and retrieving information from multiple aspects.Morison’s appropriation and mobilisation of the diagrammatic mode of representation that originated in the Middle Ages helped pave the way for the diagram,as a visual language between textuality and pictoriality,to become prevalent amongst early modern naturalists.展开更多
Considering the relatively poor robustness of quality scores for different types of distortion and the lack of mechanism for determining distortion types, a no-reference image quality assessment(NR-IQA) method based o...Considering the relatively poor robustness of quality scores for different types of distortion and the lack of mechanism for determining distortion types, a no-reference image quality assessment(NR-IQA) method based on the Ada Boost BP neural network in the wavelet domain(WABNN) is proposed. A 36-dimensional image feature vector is constructed by extracting natural scene statistics(NSS) features and local information entropy features of the distorted image wavelet sub-band coefficients in three scales. The ABNN classifier is obtained by learning the relationship between image features and distortion types. The ABNN scorer is obtained by learning the relationship between image features and image quality scores. A series of contrast experiments are carried out in the laboratory of image and video engineering(LIVE) database and TID2013 database. Experimental results show the high accuracy of the distinguishing distortion type, the high consistency with subjective scores and the high robustness of the method for distorted images. Experiment results also show the independence of the database and the relatively high operation efficiency of this method.展开更多
A computational approach is presented to handle an enlarged linear rotordynamic model whichsimultaneously includes both radial and misalignment motions.The interactive force and momentbetween the rotating and non-rota...A computational approach is presented to handle an enlarged linear rotordynamic model whichsimultaneously includes both radial and misalignment motions.The interactive force and momentbetween the rotating and non-rotating members are modeled using an adaptation of the classicalReynolds lubrication equation for incompressible laminar isoviscous films.First,the governingequation is derived and the method of solution is introduced based on a 2-dimension,9-point cen-tral difference.Second,force and moment components are computed by numerical integration ofthe film pressure distribution.Finally,the rotordynamic coefficients are yielded according to thegeneralized force gradients.展开更多
In this paper, a quantitative analysis of the opening quality in friction spinning and its main ef-fecting factors is first made. Upon this basis the Box-Hunter’s experimental design method is usedto establish the qu...In this paper, a quantitative analysis of the opening quality in friction spinning and its main ef-fecting factors is first made. Upon this basis the Box-Hunter’s experimental design method is usedto establish the quadratic regressional equations in terms of primary opening technologicalparameters and yarn quality for medium and fine count friction spinning. The results of analysisand discussion show that the proper choice of opening roller speed and its reasonable match withthe yarn count is singificant for ensuring the spinning quality index as well as reducing unevenness,thin and thick places of the yarn.展开更多
Magnetic-liquid suspension guide-way system( MLSGS) is coupled supported by permanent magnetic suspension and hydrostatic bearing. The structure and bearing mechanism of MLSGS of heavy computer numerical control( CNC)...Magnetic-liquid suspension guide-way system( MLSGS) is coupled supported by permanent magnetic suspension and hydrostatic bearing. The structure and bearing mechanism of MLSGS of heavy computer numerical control( CNC) machine tools are introduced and the mathematical expression of bearing force of bearing unit is derived and it can be broken apart into six parts which sustains directly the coordinate components of broad external load,where the air gap of permanent magnet and hydrostatic oil film can be simplified as elastic supports,the compatibility equations of deformations for oil films and air gap are presented,and then the bearing capacity calculation of the bearing unit is transformed into a determinate problem. Considering the guide-way as a rigid body,the mathematics expression between the bearing unit's bearing force and the oil film variation is linearized,and the oil pocket's bearing capacity which bears different components of the external load is calculated separately. The six components of the bearing unit are added up,and the final general mathematics expression is derived. The proposed research offers a general simple method for calculating the bearing capacity of MLSGS with complicate constraint,which can be mastered simply by engineering designer and can improve design efficiency and accuracy.展开更多
This study aimed to alert people that the harmony between human beings and nature has already become an urgent problem. All people are responsible for maintaining the harmony, which is the also the inexorable trend of...This study aimed to alert people that the harmony between human beings and nature has already become an urgent problem. All people are responsible for maintaining the harmony, which is the also the inexorable trend of historical development. Reviewing the evolution history of human kind, the relationship between human beings and nature from harmony to imbalance, from imbalance to a new harmony was analyzed from the macro perspective, and it was pointed out that the present society is in the transitional phase from imbalance to a new harmony and also a phase that people are consciously coordinating their relationship with nature. It was found through the study that a harmonious society relies on the harmony between human beings and nature, and the latter is a necessary condition for a real harmonious society, however, people always forget such a principle. The imbalanced relationship between human beings and nature has seriously influenced many aspects of social harmony, and become instable factors in China and international society, even threatened the development and survival of human beings. Thus, all people should make joint efforts in creating win-win conditions for the development between human beings and nature, and ensuring offspring a healthy and green earth.展开更多
Human life is not determined by mechanical fatalism or a single material factor;instead,based on the dualistic ontology and active force mechanism in the Unified Complex Systems Theory(UCST),it can be actively designe...Human life is not determined by mechanical fatalism or a single material factor;instead,based on the dualistic ontology and active force mechanism in the Unified Complex Systems Theory(UCST),it can be actively designed under the guidance of mind,in accordance with causal laws,and through systematic interactions.This study integrates the dualistic ontology of UCST,as well as the cooperative mechanism of active force(Fa)and passive force(Fp).Furthermore,by incorporating Master Jiqun’s philosophy of“life design”and the practical principle of“destiny establishment and transformation”from The Four Lessons of Liaofan Yuan,it constructs a three-dimensional framework for life design encompassing the dimensions of science,philosophy,and practice.The significance of this research lies in breaking through the predicament of materialism in the AI(artificial intelligence)era,explaining the autonomy and initiative of life,providing feasible pathways for life design,and ultimately achieving the in-depth integration of scientific rationality and the wisdom of traditional Eastern culture.展开更多
Defining science and demarcating it from pseudoscience are longstanding core issues in the philosophy of science.Hilbert’s traditional axiomatic standards(consistency,completeness,independence)struggle with modern co...Defining science and demarcating it from pseudoscience are longstanding core issues in the philosophy of science.Hilbert’s traditional axiomatic standards(consistency,completeness,independence)struggle with modern complex systems,while existing demarcation criteria like replicability and Popper’s falsificationism have practical limitations.Analyzing incompatibilities in complex systems,this paper proposes a revised framework:modified Hilbert axiomatic standards(clearly defined concepts,logical consistency,unrefuted axioms)and dynamic demarcation criteria.Abandoning unattainable traditional requirements of completeness and independence,it emphasizes conceptual clarity,openness,and progressiveness,offering an operational,self-consistent basis for judging scientificity.展开更多
In this paper,we consider a multiple-input single-output(MISO)Hammerstein system whose inputs and output are disturbed by unknown Gaussian white measurement noises.The parameter estimation of such a system is a typica...In this paper,we consider a multiple-input single-output(MISO)Hammerstein system whose inputs and output are disturbed by unknown Gaussian white measurement noises.The parameter estimation of such a system is a typical errors-in-variables(EIV)nonlinear system identification problem.This paper proposes a bias-correction least squares(BCLS)identification methods to compute a consistent estimate of EIV MISO Hammerstein systems from noisy data.To obtain the unbiased parameter estimates of EIV MISO Hammerstein system,the analytical expression of estimated bias for the standard least squares(LS)algorithm is derived first,which is a function about the variances of noises.And then a recursive algorithm is proposed to estimate the unknown term of noises variances from noisy data.Finally,based on bias estimation scheme,the bias caused by the correlation between the input–output signals exciting the true system and the corresponding measurement noise,resulting in unbiased parameter estimates of the EIV MISO Hammerstein system.The performance of the proposed method is demonstrated through a simulation example and a chemical continuously stirred tank reactor(CSTR)system.展开更多
In ethnopharmacology, and especially in traditional Chinese medicine, medicinal plants have been used for thousands of years. Similarly, agricultural plants have been used throughout the history of mankind. The recent...In ethnopharmacology, and especially in traditional Chinese medicine, medicinal plants have been used for thousands of years. Similarly, agricultural plants have been used throughout the history of mankind. The recent development of the genetic engineering of plants to produce plants with desirable features adds a new and growing dimension to humanity’s usage of plants. The biotechnology of plants has come of age and a plethora of bioengineering applications in this context have been delineated during the past few decades. Callus cultures and suspension cell cultures offer a wide range of usages in pharmacology and pharmacy (including Chinese medicine), as well as in agriculture and horticulture. This review provides a timely overview of the advancements that have been made with callus cultures in these scientific fields. Genetically modified callus cultures by gene technological techniques can be used for the synthesis of bioactive secondary metabolites and for the generation of plants with improved resistance against salt, draft, diseases, and pests. Although the full potential of callus plant culture technology has not yet been exploited, the time has come to develop and market more callus culture-based products.展开更多
Drop-on-demand (DOD) bioprinting has been widely used in tissue engineering due to its highthroughput efficiency and cost effectiveness. However, this type of bioprinting involves challenges such as satellite generati...Drop-on-demand (DOD) bioprinting has been widely used in tissue engineering due to its highthroughput efficiency and cost effectiveness. However, this type of bioprinting involves challenges such as satellite generation, too-large droplet generation, and too-low droplet speed. These challenges reduce the stability and precision of DOD printing, disorder cell arrays, and hence generate further structural errors. In this paper, a multi-objective optimization (MOO) design method for DOD printing parameters through fully connected neural networks (FCNNs) is proposed in order to solve these challenges. The MOO problem comprises two objective functions: to develop the satellite formation model with FCNNs;and to decrease droplet diameter and increase droplet speed. A hybrid multi-subgradient descent bundle method with an adaptive learning rate algorithm (HMSGDBA), which combines the multisubgradient descent bundle (MSGDB) method with Adam algorithm, is introduced in order to search for the Pareto-optimal set for the MOO problem. The superiority of HMSGDBA is demonstrated through comparative studies with the MSGDB method. The experimental results show that a single droplet can be printed stably and the droplet speed can be increased from 0.88 to 2.08 m·s^-1 after optimization with the proposed method. The proposed method can improve both printing precision and stability, and is useful in realizing precise cell arrays and complex biological functions. Furthermore, it can be used to obtain guidelines for the setup of cell-printing experimental platforms.展开更多
A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the t...A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.展开更多
By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the expe...By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the experiment results agree with the calculated ones.This method only re-quires calculation of lower-order transfer matrix and determinant values,so that, it can be done ona minicomputer such as IBM/PC.The method adopted in this paper is also suitable for vibrationanalysis of other types of linkages.展开更多
A general shape of tensile stress-strain curves of woven fabrics is first recognised by puttingtested and predicted results together.An exponential function with two parameters is then selectedfor the prediction of te...A general shape of tensile stress-strain curves of woven fabrics is first recognised by puttingtested and predicted results together.An exponential function with two parameters is then selectedfor the prediction of tensile stress-strain relationship.The predicted results by using the proposedfunction show excellent agreement with experimental data.展开更多
Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize th...Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.展开更多
In this work, author evaluated past theories and perspectives behind the definitions of science and/or branches of science. Also some of the philosophers of science and their specific philosophical interests were expr...In this work, author evaluated past theories and perspectives behind the definitions of science and/or branches of science. Also some of the philosophers of science and their specific philosophical interests were expressed. Author considered some type of interactions between some disciplines to determine, to solve the philosophical/scientific problems and to define the possible solutions. The purposes of this article are： （i） to define new synthesis method, （ii） to define new perspective for the philosophy of science, （iii） to define relation between new philosophy perspective and philosophy of science, （iv） to define and organize name, number, relations, and correct structure between special science branches and philosophy of science, （v） to define necessary and sufficient number of branches for philosophy of science, （vi） to define and express the importance and place of new philosophy of science perspective in the new system, （vii） to extend the definition/limits of philosophy of science, （viii） to re-define meanings of some philosophical/scientific theories, （ix） to define systematic solution for the conflicts, problems, confusions about philosophy of science, sciences and branches of science, （x） to define new branches of science, （xi） to re-construct branches and hierarchy of science, （xii） to define new theories about science and branches of science. Author considered R-Synthesis as a method for the evaluation oftbe philosophy, philosophy of science, sciences and branches of science. This R-Synthesis includes evaluation of eight categories of general/specific perspective, 21-dimensions, and 12 general subjects （with related scope and contents） for the past 12,000 years. It is a kind of synthesis of science and non-science, physical science and non-physical science, religious science and non-religious science, and others. In this article, author defined 27 possible definitive/certain result cases for this new synthesis. Author defined the possible formation stages shortly to express new disciplines, new constructional and/or complementary theories. These theories are considered to define 21 major effective disciplines. New philosophy perspective is defined （R-Philosophy） shortly. New perspective and sub branches are defined for the philosophy of science. Major sciences are defined due to new basic philosophies. 42-basic components are defined for each science branch. New and/or re-constructed sciences, branches of science, basic sciences, and new hierarchy of science are defined with figure. Electromagnetic sciences, information sciences, and system sciences are defined specifically. Hybrid Sciences, New Era Science, and Ideal Scientific System are defined with general/specific figure. Relation between the some old branches and new branches of science was expressed generally due to new perspective of philosophy of science.展开更多
文摘Aims and scope Journal of Systems Engineering and Electronics,keeping abreast with the development trend of science and technology worldwide,reports the latest developments and achievements in both theoretical and practical aspects of systems engineering,electronics and related research areas.The journal welcomes high quality original papers from a wide range of countries.The scope of the journal includes systems engineering,military systems,electronic technology,defense electronic technology,control theory and practice,software algorithm and simulation,reliability,computer development and application,and other topics in all related fields.
文摘An analysis is made of the problem of sound radiation from infinite one-dimensional plateson elastic foundation, when the plates are subjected to the action of harmonic line forces movingat subsonic speeds (M 【 1). The expressions of nondimensional sound power are formulated andthe asymptotic forms of sound power in the low frequency regions are derived. The radiatedsound power is shown as a function of the stiffness of elastic foundation, in terms of stiffness fac-torψ, the moving speed of line force, in terms of Math number M, and the frequency, in termsof wavenumber ratio γ . The effects of the parameter ψ in conjunction with the parameters Mand γ on the radiated sound power level and the phenomenon of coincidence radiation are alsoinvestigated in detail.
基金supported by the National Natural Science Foundation of China(Nos.52372403 and U2268211)the Natural Science Foundation of Sichuan Province(No.2022NSFSC0034),China+1 种基金the National Railway Group Science and Technology Program(No.2023J071)the Traction Power State Key Laboratory of the Independent Research and Development Projects(No.2022TPL-T02),China.
文摘In recent years,train-tail swaying of 160 km/h electric multiple units(EMUs)inside single-line tunnels has been heavily researched,because the issue needs to be solved urgently.In this paper,a co-simulation model of vortex-induced vibration(VIV)of the tail car body is established,and the aerodynamics of train-tail swaying is studied.The simulation results were confirmed through a field test of operating EMUs.Furthermore,the influence mechanism of train-tail swaying on the wake flow field is studied in detail through a wind-tunnel experiment and a simulation of a reduced-scaled train model.The results demonstrate that the aerodynamic force frequency(i.e.,vortex-induced frequency)of the train tail increases linearly with train speed.When the train runs at 130 km/h,with a small amplitude of train-tail swaying(within 10 mm),the vortex-induced frequency is 1.7 Hz,which primarily depends on the nose shape of the train tail.After the tail car body nose is extended,the vortex-induced frequency is decreased.As the swaying amplitude of the train tail increases(exceeding 25 mm),the separation point of the high-intensity vortex in the train wake shifts downstream to the nose tip,and the vortex-induced frequency shifts from 1.7 Hz to the nearby car body hunting(i.e.,the primary hunting)frequency of 1.3 Hz,which leads to the frequency-locking phenomenon of VIV,and the resonance intensifies train-tail swaying.For the motor vehicle of the train tail,optimization of the yaw damper to improve its primary hunting stability can effectively alleviate train-tail swaying inside single-line tunnels.Optimization of the tail car body nose shape reduces the amplitude of the vortex-induced force,thereby weakening the aerodynamic effect and solving the problem of train-tail swaying inside the single-line tunnels.
基金supported by the National Defense Pre-research Project of China during the 12th Five-year Plan Period(4040570201)Innovation Project of Military Academy(ZYX14060014)
文摘This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.
文摘Diagrams as a visual technique played a key role in early modern natural history.Robert Morison,a Scottish botanist and the first Professor of Botany at Oxford University,made a noteworthy early attempt in the 17th century to promote the use of diagrams in plant taxonomy.By pioneering the use of diagrams as the core of his botanical monographs,Morison inverted the order in which text and diagrams are read in natural history books and made diagrams more than a mere adjunct to the main text.Morison also consciously aligned the structure of the diagrams with the spatial arrangement of his seed collection and the Oxford Botanic Garden,so that the diagrams functioned productively as a means of bridging difierent botanical practices and retrieving information from multiple aspects.Morison’s appropriation and mobilisation of the diagrammatic mode of representation that originated in the Middle Ages helped pave the way for the diagram,as a visual language between textuality and pictoriality,to become prevalent amongst early modern naturalists.
基金supported by the National Natural Science Foundation of China(61471194 61705104)+1 种基金the Science and Technology on Avionics Integration Laboratory and Aeronautical Science Foundation of China(20155552050)the Natural Science Foundation of Jiangsu Province(BK20170804)
文摘Considering the relatively poor robustness of quality scores for different types of distortion and the lack of mechanism for determining distortion types, a no-reference image quality assessment(NR-IQA) method based on the Ada Boost BP neural network in the wavelet domain(WABNN) is proposed. A 36-dimensional image feature vector is constructed by extracting natural scene statistics(NSS) features and local information entropy features of the distorted image wavelet sub-band coefficients in three scales. The ABNN classifier is obtained by learning the relationship between image features and distortion types. The ABNN scorer is obtained by learning the relationship between image features and image quality scores. A series of contrast experiments are carried out in the laboratory of image and video engineering(LIVE) database and TID2013 database. Experimental results show the high accuracy of the distinguishing distortion type, the high consistency with subjective scores and the high robustness of the method for distorted images. Experiment results also show the independence of the database and the relatively high operation efficiency of this method.
文摘A computational approach is presented to handle an enlarged linear rotordynamic model whichsimultaneously includes both radial and misalignment motions.The interactive force and momentbetween the rotating and non-rotating members are modeled using an adaptation of the classicalReynolds lubrication equation for incompressible laminar isoviscous films.First,the governingequation is derived and the method of solution is introduced based on a 2-dimension,9-point cen-tral difference.Second,force and moment components are computed by numerical integration ofthe film pressure distribution.Finally,the rotordynamic coefficients are yielded according to thegeneralized force gradients.
文摘In this paper, a quantitative analysis of the opening quality in friction spinning and its main ef-fecting factors is first made. Upon this basis the Box-Hunter’s experimental design method is usedto establish the quadratic regressional equations in terms of primary opening technologicalparameters and yarn quality for medium and fine count friction spinning. The results of analysisand discussion show that the proper choice of opening roller speed and its reasonable match withthe yarn count is singificant for ensuring the spinning quality index as well as reducing unevenness,thin and thick places of the yarn.
基金Supported by the National Natural Science Foundation of China(No.51705445)the Natural Science Foundation of Hebei Province(No.E2016203324)the Provincial and Ministerial Level Scientific Research Institutions Open Fund of Civil Aviation University of China
文摘Magnetic-liquid suspension guide-way system( MLSGS) is coupled supported by permanent magnetic suspension and hydrostatic bearing. The structure and bearing mechanism of MLSGS of heavy computer numerical control( CNC) machine tools are introduced and the mathematical expression of bearing force of bearing unit is derived and it can be broken apart into six parts which sustains directly the coordinate components of broad external load,where the air gap of permanent magnet and hydrostatic oil film can be simplified as elastic supports,the compatibility equations of deformations for oil films and air gap are presented,and then the bearing capacity calculation of the bearing unit is transformed into a determinate problem. Considering the guide-way as a rigid body,the mathematics expression between the bearing unit's bearing force and the oil film variation is linearized,and the oil pocket's bearing capacity which bears different components of the external load is calculated separately. The six components of the bearing unit are added up,and the final general mathematics expression is derived. The proposed research offers a general simple method for calculating the bearing capacity of MLSGS with complicate constraint,which can be mastered simply by engineering designer and can improve design efficiency and accuracy.
文摘This study aimed to alert people that the harmony between human beings and nature has already become an urgent problem. All people are responsible for maintaining the harmony, which is the also the inexorable trend of historical development. Reviewing the evolution history of human kind, the relationship between human beings and nature from harmony to imbalance, from imbalance to a new harmony was analyzed from the macro perspective, and it was pointed out that the present society is in the transitional phase from imbalance to a new harmony and also a phase that people are consciously coordinating their relationship with nature. It was found through the study that a harmonious society relies on the harmony between human beings and nature, and the latter is a necessary condition for a real harmonious society, however, people always forget such a principle. The imbalanced relationship between human beings and nature has seriously influenced many aspects of social harmony, and become instable factors in China and international society, even threatened the development and survival of human beings. Thus, all people should make joint efforts in creating win-win conditions for the development between human beings and nature, and ensuring offspring a healthy and green earth.
基金supported by the start-up funding from Westlake University under Grant Number 041030150118 and the scientific research project of Westlake University“Theoretical Research and Demonstration Application of Complex Systems and Deep-Sea Technology(Phase I)”under Grant Number WU2025A006.
文摘Human life is not determined by mechanical fatalism or a single material factor;instead,based on the dualistic ontology and active force mechanism in the Unified Complex Systems Theory(UCST),it can be actively designed under the guidance of mind,in accordance with causal laws,and through systematic interactions.This study integrates the dualistic ontology of UCST,as well as the cooperative mechanism of active force(Fa)and passive force(Fp).Furthermore,by incorporating Master Jiqun’s philosophy of“life design”and the practical principle of“destiny establishment and transformation”from The Four Lessons of Liaofan Yuan,it constructs a three-dimensional framework for life design encompassing the dimensions of science,philosophy,and practice.The significance of this research lies in breaking through the predicament of materialism in the AI(artificial intelligence)era,explaining the autonomy and initiative of life,providing feasible pathways for life design,and ultimately achieving the in-depth integration of scientific rationality and the wisdom of traditional Eastern culture.
基金supported by the start-up funding from Westlake University under Grant Number 041030150118 and the scientific research project of Westlake University“Theoretical Research and Demonstration Application of Complex Systems and Deep-Sea Technology(Phase I)”under Grant Number WU2025A006.
文摘Defining science and demarcating it from pseudoscience are longstanding core issues in the philosophy of science.Hilbert’s traditional axiomatic standards(consistency,completeness,independence)struggle with modern complex systems,while existing demarcation criteria like replicability and Popper’s falsificationism have practical limitations.Analyzing incompatibilities in complex systems,this paper proposes a revised framework:modified Hilbert axiomatic standards(clearly defined concepts,logical consistency,unrefuted axioms)and dynamic demarcation criteria.Abandoning unattainable traditional requirements of completeness and independence,it emphasizes conceptual clarity,openness,and progressiveness,offering an operational,self-consistent basis for judging scientificity.
基金supported in part by the National Natural Science Foundation of China(62373070 and 52272388)in part by the Chongqing Natural Science Foundation(CSTB2024NSCQ-QCXMX0054,CSTB2022NSCQ-MSX1225 and CSTC2024YCJH-BGZXM0042)in part by the Key Research and Development Project of Anhui Province(202304a05020060).
文摘In this paper,we consider a multiple-input single-output(MISO)Hammerstein system whose inputs and output are disturbed by unknown Gaussian white measurement noises.The parameter estimation of such a system is a typical errors-in-variables(EIV)nonlinear system identification problem.This paper proposes a bias-correction least squares(BCLS)identification methods to compute a consistent estimate of EIV MISO Hammerstein systems from noisy data.To obtain the unbiased parameter estimates of EIV MISO Hammerstein system,the analytical expression of estimated bias for the standard least squares(LS)algorithm is derived first,which is a function about the variances of noises.And then a recursive algorithm is proposed to estimate the unknown term of noises variances from noisy data.Finally,based on bias estimation scheme,the bias caused by the correlation between the input–output signals exciting the true system and the corresponding measurement noise,resulting in unbiased parameter estimates of the EIV MISO Hammerstein system.The performance of the proposed method is demonstrated through a simulation example and a chemical continuously stirred tank reactor(CSTR)system.
文摘In ethnopharmacology, and especially in traditional Chinese medicine, medicinal plants have been used for thousands of years. Similarly, agricultural plants have been used throughout the history of mankind. The recent development of the genetic engineering of plants to produce plants with desirable features adds a new and growing dimension to humanity’s usage of plants. The biotechnology of plants has come of age and a plethora of bioengineering applications in this context have been delineated during the past few decades. Callus cultures and suspension cell cultures offer a wide range of usages in pharmacology and pharmacy (including Chinese medicine), as well as in agriculture and horticulture. This review provides a timely overview of the advancements that have been made with callus cultures in these scientific fields. Genetically modified callus cultures by gene technological techniques can be used for the synthesis of bioactive secondary metabolites and for the generation of plants with improved resistance against salt, draft, diseases, and pests. Although the full potential of callus plant culture technology has not yet been exploited, the time has come to develop and market more callus culture-based products.
文摘Drop-on-demand (DOD) bioprinting has been widely used in tissue engineering due to its highthroughput efficiency and cost effectiveness. However, this type of bioprinting involves challenges such as satellite generation, too-large droplet generation, and too-low droplet speed. These challenges reduce the stability and precision of DOD printing, disorder cell arrays, and hence generate further structural errors. In this paper, a multi-objective optimization (MOO) design method for DOD printing parameters through fully connected neural networks (FCNNs) is proposed in order to solve these challenges. The MOO problem comprises two objective functions: to develop the satellite formation model with FCNNs;and to decrease droplet diameter and increase droplet speed. A hybrid multi-subgradient descent bundle method with an adaptive learning rate algorithm (HMSGDBA), which combines the multisubgradient descent bundle (MSGDB) method with Adam algorithm, is introduced in order to search for the Pareto-optimal set for the MOO problem. The superiority of HMSGDBA is demonstrated through comparative studies with the MSGDB method. The experimental results show that a single droplet can be printed stably and the droplet speed can be increased from 0.88 to 2.08 m·s^-1 after optimization with the proposed method. The proposed method can improve both printing precision and stability, and is useful in realizing precise cell arrays and complex biological functions. Furthermore, it can be used to obtain guidelines for the setup of cell-printing experimental platforms.
基金supported by the National Natural Science Foundation of China(61773398 61703421)
文摘A prescribed performance neural controller to guarantee tracking quality is addressed for the near space kinetic kill vehicle (NSKKV) to meet the state constraints caused by side window detection. Different from the traditional prescribed performance control in which the shape of the performance function is constant, this paper exploits new performance functions which can change the shape of their function according to different symbols of initial errors and can ensure the error convergence with a small overshoot. The neural backstepping control and the minimal learning parameters (MLP) technology are employed for exploring a prescribed performance controller (PPC) that provides robust tracking attitude reference trajectories. The highlight is that the transient performance of tracking errors is satisfactory and the computational load of neural approximation is low. The pseudo rate (PSR) modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation and high accuracy.
文摘By using transfer matrix,the lower-order natural frequencies of the Watt type planar six-barlinkage are calculated in this paper.The experiment of the modal analysis is done with the SignalProcessor 7T17S,and the experiment results agree with the calculated ones.This method only re-quires calculation of lower-order transfer matrix and determinant values,so that, it can be done ona minicomputer such as IBM/PC.The method adopted in this paper is also suitable for vibrationanalysis of other types of linkages.
文摘A general shape of tensile stress-strain curves of woven fabrics is first recognised by puttingtested and predicted results together.An exponential function with two parameters is then selectedfor the prediction of tensile stress-strain relationship.The predicted results by using the proposedfunction show excellent agreement with experimental data.
基金Projects(52274108,U2341265)supported by the National Natural Science Foundation of ChinaProject(2022YFC2904103)supported by the National Key Research and Development Program of China。
文摘Utilizing mine solid waste as a partial cement substitute(CS)to develop new cementitious materials is a significant technological innovation that will decrease the expenses associated with filling mining.To realize the resource utilization of magnesium slag(MS)and blast furnace slag(BFS),the effects of different contents of MS and BFS as partial CSs on the deformation and energy characteristics of cemented tailings backfill on different curing ages(3,7,and 28 d)were discussed.Meanwhile,the destabilization failure energy criterion of the backfill was established from the direction of energy change.The results show that the strength of all backfills increased with increasing curing age,and the strengths of the backfills exceeded 1.342 MPa on day 28.The backfill with 50%BFS+50%cement has the best performance in mechanical properties(the maximum strength can reach 6.129 MPa)and is the best choice among these CS combinations.The trend in peak strain and elastic modulus of the backfill with increasing curing age may vary depending on the CS combination.The energy index at peak stress of the backfill with BFS as a partial CS was significantly higher than that of the backfill under other CS combinations.In contrast,the enhancement of the energy index when MS was used as a partial CS was not as significant as BFS.Sharp changes in the energy consumption ratio after continuous smooth changes can be used as a criterion for destabilization and failure of the backfill.The research results can provide guidance for the application of MS and BFS as partial CSs in mine filling.
文摘In this work, author evaluated past theories and perspectives behind the definitions of science and/or branches of science. Also some of the philosophers of science and their specific philosophical interests were expressed. Author considered some type of interactions between some disciplines to determine, to solve the philosophical/scientific problems and to define the possible solutions. The purposes of this article are： （i） to define new synthesis method, （ii） to define new perspective for the philosophy of science, （iii） to define relation between new philosophy perspective and philosophy of science, （iv） to define and organize name, number, relations, and correct structure between special science branches and philosophy of science, （v） to define necessary and sufficient number of branches for philosophy of science, （vi） to define and express the importance and place of new philosophy of science perspective in the new system, （vii） to extend the definition/limits of philosophy of science, （viii） to re-define meanings of some philosophical/scientific theories, （ix） to define systematic solution for the conflicts, problems, confusions about philosophy of science, sciences and branches of science, （x） to define new branches of science, （xi） to re-construct branches and hierarchy of science, （xii） to define new theories about science and branches of science. Author considered R-Synthesis as a method for the evaluation oftbe philosophy, philosophy of science, sciences and branches of science. This R-Synthesis includes evaluation of eight categories of general/specific perspective, 21-dimensions, and 12 general subjects （with related scope and contents） for the past 12,000 years. It is a kind of synthesis of science and non-science, physical science and non-physical science, religious science and non-religious science, and others. In this article, author defined 27 possible definitive/certain result cases for this new synthesis. Author defined the possible formation stages shortly to express new disciplines, new constructional and/or complementary theories. These theories are considered to define 21 major effective disciplines. New philosophy perspective is defined （R-Philosophy） shortly. New perspective and sub branches are defined for the philosophy of science. Major sciences are defined due to new basic philosophies. 42-basic components are defined for each science branch. New and/or re-constructed sciences, branches of science, basic sciences, and new hierarchy of science are defined with figure. Electromagnetic sciences, information sciences, and system sciences are defined specifically. Hybrid Sciences, New Era Science, and Ideal Scientific System are defined with general/specific figure. Relation between the some old branches and new branches of science was expressed generally due to new perspective of philosophy of science.
