A general procedure to capture the 'dynanmic Stiffness' is presented in this paper. The governing equations of motion are formulated for an arbitrary flexible body in large overall motion based on Kane's ...A general procedure to capture the 'dynanmic Stiffness' is presented in this paper. The governing equations of motion are formulated for an arbitrary flexible body in large overall motion based on Kane's equations . The linearization is performed peroperly by means of geometrically nonlinear straindisplacement relations and the nonlinear expression of angular velocity so that the 'dynamical stiffness' terms can be captured naturally in a general tcase. The concept and formulations of partial velocity and angular velocity arrays of Huston's method are extended to the flexible body and form the basis of the analysis. The validity and generality of the procedure presented in the paper are verified by numerical results of its application in both the beam and plate models.展开更多
Locality preserving projection (LPP) is a typical and popular dimensionality reduction (DR) method,and it can potentially find discriminative projection directions by preserving the local geometric structure in da...Locality preserving projection (LPP) is a typical and popular dimensionality reduction (DR) method,and it can potentially find discriminative projection directions by preserving the local geometric structure in data. However,LPP is based on the neighborhood graph artificially constructed from the original data,and the performance of LPP relies on how well the nearest neighbor criterion work in the original space. To address this issue,a novel DR algorithm,called the self-dependent LPP (sdLPP) is proposed. And it is based on the fact that the nearest neighbor criterion usually achieves better performance in LPP transformed space than that in the original space. Firstly,LPP is performed based on the typical neighborhood graph; then,a new neighborhood graph is constructed in LPP transformed space and repeats LPP. Furthermore,a new criterion,called the improved Laplacian score,is developed as an empirical reference for the discriminative power and the iterative termination. Finally,the feasibility and the effectiveness of the method are verified by several publicly available UCI and face data sets with promising results.展开更多
The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing m...The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.展开更多
This paper presents an advanced and integrated research approach to longwall mining-induced strata move- ment, stress changes, fractures, and gas flow dynamics with actual examples of its application from recent studi...This paper presents an advanced and integrated research approach to longwall mining-induced strata move- ment, stress changes, fractures, and gas flow dynamics with actual examples of its application from recent studies for coextraction of coal and methane development at Huainan Mining Group in China, in a deep and multi-seam mining environment. The advanced approach takes advantage of the latest techniques in Australia for mine scale geotechnical characterisation, field measurement, monitoring and numerical modelling. Key techniques described in this paper include coal mine site 3D geotechnical characterisation methods, surface deep downhole multi-point extensometers and piezometers for overburden displacement and pore pressure measurements during mining, tracer gas tests for goal gas flow patterns, and advanced numerical modelling codes for coupled coal mine strata, water and gas simulations, and longwall goaf gas ttow investigations. This integrated approach has resulted in significant insights into the complex dynamic imeraction between strata, groundwater, and gas during mining at Huainan Mining Group in recent years. Based on the lindings from the extensive field monitoring and numerical modelling studies, a three-dimensional annular-shaped over-lying zone along the perimeter of the longwall panel was identified for optimal methane drainage during mining.展开更多
The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. ...The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°–9°N and 91°–94°W and by 6°30′–7°30′N and 96°–97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29℃. The sex ratio of the total catch was 3.75:1(female: male). The mantle length of the squid ranged from 211 to 355 mm(male) and from 204 to 429 mm(female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length(mm) and body weight(g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size(mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs(70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.展开更多
Myoglobin has important biological functions in storing and transporting small diatomic molecules in human body. Two possible orientations of carbon monoxide (CO) in the heme distal pocket (named as BI and B2 state...Myoglobin has important biological functions in storing and transporting small diatomic molecules in human body. Two possible orientations of carbon monoxide (CO) in the heme distal pocket (named as BI and B2 states) of myoglobin have been experimentally indicated. In this study, ab initio quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulation of CO in myoglobin was carried out to investigate the two possible B states. Our results demonstrate that the B1 and B2 states correspond to Fe... CO (with carbon atom closer to iron center of heme) and Fe... OC (with oxygen atom closer to Fe), by comparing with the experimental infrared spectrum. QM electrostatic polarization effect on CO brought from the protein and solvent environment is the main driving force, which anchors CO in two distinctive orientations and hinders its rotation. The calculated vibrational frequency shift between the state B1 and B2 is 13.1 cm-1, which is in good agreement with experimental value of 11.5 cm-1. This study also shows that the electric field produced by the solvent plays an important role in assisting protein functions by exerting directional electric field at the active site of the protein, From residue-based electric field decomposition, several residues were found to have most contributions to the total electric field at the CO center, including a few charged residues and three adjacent uncharged polar residues (namely, HIS64, ILE107, and PHE43). This study provides new physical insights on rational design of enzyme with higher electric field at the active site.展开更多
Pre-knowledge of machined surface roughness is the key to improve whole machining efficiency and meanwhile reduce the expenditure in machining optical glass components.In order to predict the surface roughness in ultr...Pre-knowledge of machined surface roughness is the key to improve whole machining efficiency and meanwhile reduce the expenditure in machining optical glass components.In order to predict the surface roughness in ultrasonic vibration assisted grinding of brittle materials,the surface morphologies of grinding wheel were obtained firstly in the present work,the grinding wheel model was developed and the abrasive trajectories in ultrasonic vibration assisted grinding were also investigated,the theoretical model for surface roughness was developed based on the above analysis.The prediction model was developed by using Gaussian processing regression(GPR)due to the influence of brittle fracture on machined surface roughness.In order to validate both the proposed theoretical and GPR models,32sets of experiments of ultrasonic vibration assisted grinding of BK7optical glass were carried out.Experimental results show that the average relative errors of the theoretical model and GPR prediction model are13.11%and8.12%,respectively.The GPR prediction results can match well with the experimental results.展开更多
The neutral gauge boson BH with the mass of hundreds GeV is the lightest particle predicted by the littlest Higgs (LH) model, and such particle should be the first signal of the LH model at the planed ILC if it exis...The neutral gauge boson BH with the mass of hundreds GeV is the lightest particle predicted by the littlest Higgs (LH) model, and such particle should be the first signal of the LH model at the planed ILC if it exists indeed. In this paper, we study some processes of the BH production associated with the fermion pair at the ILC, i.e., γγ→ ff^- BH. The studies show that the most promising processes to detect BH amongγγ→ ff^- BH are γγ→ l'^+l'^-BH (l' = e,μ), and they can produce the sufficient signals in most parameter space preferred by the electroweak precision data at the ILC. On the other hand, the signal produced via the certain BH decay modes is typical and such signal can be easily identified from the SM background. Therefore, BH, the lightest gauge boson in the LH model, would be detectable at the photon collider realized at the ILC.展开更多
In order to classify the minimal hepatic encephalopathy (MHE) patients from healthy controls, the independent component analysis (ICA) is used to generate the default mode network (DMN) from resting-state functi...In order to classify the minimal hepatic encephalopathy (MHE) patients from healthy controls, the independent component analysis (ICA) is used to generate the default mode network (DMN) from resting-state functional magnetic resonance imaging (fMRI). Then a Bayesian voxel- wised method, graphical-model-based multivariate analysis (GAMMA), is used to explore the associations between abnormal functional integration within DMN and clinical variable. Without any prior knowledge, five machine learning methods, namely, support vector machines (SVMs), classification and regression trees ( CART ), logistic regression, the Bayesian network, and C4.5, are applied to the classification. The functional integration patterns were alternative within DMN, which have the power to predict MHE with an accuracy of 98%. The GAMMA method generating functional integration patterns within DMN can become a simple, objective, and common imaging biomarker for detecting MIIE and can serve as a supplement to the existing diagnostic methods.展开更多
We report physicochemical characteristics of various kinds of liquid milk commercially available in Pakistan in comparison with those of fresh natural milk from animals. Milk samples were collected from local markets ...We report physicochemical characteristics of various kinds of liquid milk commercially available in Pakistan in comparison with those of fresh natural milk from animals. Milk samples were collected from local markets at Peshawar, Pakistan, and analyzed for their physical features, including moisture, total solids, specific gravity, conductivity, viscosity and titratable acidity (lactic acid equivalent), and chemical components and macro-minerals, including total protein, casein, lactose, ash and minerals (Na, K and Mg). These items were compared with the physicochemical characteristics of the fresh natural milk samples from buffalo, cow and goat. The results were also compared with reported nutritional quality of milk from various countries and World Health Organization (WHO) standards. We found that all the physical features and chemical components of commercially available milk in Pakistan markets meet WHO's requirements, except for Na, K, Ca and Mg, which are below the standards.展开更多
An adaptive topology learning approach is proposed to learn the topology of a practical camera network in an unsupervised way. The nodes are modeled by the Gaussian mixture model. The connectivity between nodes is jud...An adaptive topology learning approach is proposed to learn the topology of a practical camera network in an unsupervised way. The nodes are modeled by the Gaussian mixture model. The connectivity between nodes is judged by their cross-correlation function, which is also used to calculate their transition time distribution. The mutual information of the connected node pair is employed for transition probability calculation. A false link eliminating approach is proposed, along with a topology updating strategy to improve the learned topology. A real monitoring system with five disjoint cameras is built for experiments. Comparative results with traditional methods show that the proposed method is more accurate in topology learning and is more robust to environmental changes.展开更多
The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs (LH) model, we study the process e-γ → veW^-H and calculate the contributions of the LH m...The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs (LH) model, we study the process e-γ → veW^-H and calculate the contributions of the LH model to the cross section of this process. The results show that in most of the parameter spaces preferred by the electroweak precision data, the value of the relative correction is larger than 10%. Such correction to the process e-γ →veW^-H is large enough to be detected via e-γ collisions in the future high energy linear e^+ e^- collider (ILC) experiment with the c.m. energy √s = 500 GeV and a yearly integrated luminosity £ = 100fb^-1, which will give an idea/way to test the model.展开更多
Due to the influence of terrain structure,meteorological conditions and various factors,there are anomalous data in automatic dependent surveillance-broadcast(ADS-B)message.The ADS-B equipment can be used for position...Due to the influence of terrain structure,meteorological conditions and various factors,there are anomalous data in automatic dependent surveillance-broadcast(ADS-B)message.The ADS-B equipment can be used for positioning of general aviation aircraft.Aim to acquire the accurate position information of aircraft and detect anomaly data,the ADS-B anomaly data detection model based on deep learning and difference of Gaussian(DoG)approach is proposed.First,according to the characteristic of ADS-B data,the ADS-B position data are transformed into the coordinate system.And the origin of the coordinate system is set up as the take-off point.Then,based on the kinematic principle,the ADS-B anomaly data can be removed.Moreover,the details of the ADS-B position data can be got by the DoG approach.Finally,the long short-term memory(LSTM)neural network is used to optimize the recurrent neural network(RNN)with severe gradient reduction for processing ADS-B data.The position data of ADS-B are reconstructed by the sequence to sequence(seq2seq)model which is composed of LSTM neural network,and the reconstruction error is used to detect the anomalous data.Based on the real flight data of general aviation aircraft,the simulation results show that the anomaly data can be detected effectively by the proposed method of reconstructing ADS-B data with the seq2seq model,and its running time is reduced.Compared with the RNN,the accuracy of anomaly detection is increased by 2.7%.The performance of the proposed model is better than that of the traditional anomaly detection models.展开更多
The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics...The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics, while enormous successful in physics, have been in an awkward situation of wanting a consistent dynamical understanding. Here we present from a formal point of view an exploration of the connection between thermodynamics and Darwinian dynamics and a few related topics. We first show that the stochasticity in Darwinian dynamics implies the existence temperature, hence the canonical distribution of Boltzmann-Gibbs type. In term of relative entropy the Second Law of thermodynamics is dynamically demonstrated without detailed balance condition, and is valid regardless of size of the system. In particular, the dynamical component responsible for breaking detailed balance condition does not contribute to the change of the relative entropy. Two types of stochastic dynamical equalities of current interest are explicitly discussed in the present approach: One is based on Feynman-Kac formula and another is a generalization of Einstein relation. Both are directly accessible to experimental tests. Our demonstration indicates that Darwinian dynamics represents logically a simple and straightforward starting point for statistical mechanics and thermodynamics and is complementary to and consistent with conservative dynamics that dominates the physical sciences. Present exploration suggests the existence of a unified stochastic dynamical framework both near and far from equilibrium.展开更多
It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest sc...It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest scientific heritage, represented by the so-called golden age of Euclid, Archimedes and Apollonius, Ⅲ-Ⅱ century BC. Well, it is believed that with our complex concept of tradition of thought within which we insert not only epistemological concepts but also philosophical principles, historical and social frameworks, in stasis or in strong movement, processed by us, it is possible better interpret that happy moment of scientific constructions of the third and second century BC, as a result of the valorization of the deep travail and serious battle that preceded it between the fourth and fifth century BC. It is investigated in particular in our paper the development of astronomical thought between the fifth and fourth centuries BC, in the ancient Greek thought, and at last a particular presumed criticism by Archimedes in his Sandreckoner to Aristarchus.展开更多
Objective:To investigate the neural electrophysiologieal activity underlying Chinese and Eng- lish Stroop tasks for Chinese English bilinguals.Methods:Event-related potentials(ERPs)were recorded in 14 Chinese bilingua...Objective:To investigate the neural electrophysiologieal activity underlying Chinese and Eng- lish Stroop tasks for Chinese English bilinguals.Methods:Event-related potentials(ERPs)were recorded in 14 Chinese bilinguals with a moderate command of English when they performed the Stroop task pre- sented in English words and Chinese characters,respectively.Results:In Chinese task version,it was found an increased positivity over bilateral front-polar regions on incongruent trials compared with congru- ent trials,followed by an increased negativity over fronto-central region and an increased positivity over occipital region.While in English task version,only the increased negativity was observed over fronto-cen- tral region,but with reduced amplitude and anterior distribution.Conclusion:This increased negativity was proposed as an index of the resolution processes of conflicting information in the incongruent situa- tion.The increased positivity over occipital region on Chinese incongruent trials may indicate visually rechecking effect for Chinese character.展开更多
Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed a...Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.展开更多
文摘A general procedure to capture the 'dynanmic Stiffness' is presented in this paper. The governing equations of motion are formulated for an arbitrary flexible body in large overall motion based on Kane's equations . The linearization is performed peroperly by means of geometrically nonlinear straindisplacement relations and the nonlinear expression of angular velocity so that the 'dynamical stiffness' terms can be captured naturally in a general tcase. The concept and formulations of partial velocity and angular velocity arrays of Huston's method are extended to the flexible body and form the basis of the analysis. The validity and generality of the procedure presented in the paper are verified by numerical results of its application in both the beam and plate models.
基金Supported by the National Natural Science Foundation of China (60973097)the Scientific Research Foundation of Liaocheng University(X0810029)~~
文摘Locality preserving projection (LPP) is a typical and popular dimensionality reduction (DR) method,and it can potentially find discriminative projection directions by preserving the local geometric structure in data. However,LPP is based on the neighborhood graph artificially constructed from the original data,and the performance of LPP relies on how well the nearest neighbor criterion work in the original space. To address this issue,a novel DR algorithm,called the self-dependent LPP (sdLPP) is proposed. And it is based on the fact that the nearest neighbor criterion usually achieves better performance in LPP transformed space than that in the original space. Firstly,LPP is performed based on the typical neighborhood graph; then,a new neighborhood graph is constructed in LPP transformed space and repeats LPP. Furthermore,a new criterion,called the improved Laplacian score,is developed as an empirical reference for the discriminative power and the iterative termination. Finally,the feasibility and the effectiveness of the method are verified by several publicly available UCI and face data sets with promising results.
基金Ministry of Science and Higher Education of the Russian Federation(scientific topic No.0137-2019-0023).
文摘The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.
文摘This paper presents an advanced and integrated research approach to longwall mining-induced strata move- ment, stress changes, fractures, and gas flow dynamics with actual examples of its application from recent studies for coextraction of coal and methane development at Huainan Mining Group in China, in a deep and multi-seam mining environment. The advanced approach takes advantage of the latest techniques in Australia for mine scale geotechnical characterisation, field measurement, monitoring and numerical modelling. Key techniques described in this paper include coal mine site 3D geotechnical characterisation methods, surface deep downhole multi-point extensometers and piezometers for overburden displacement and pore pressure measurements during mining, tracer gas tests for goal gas flow patterns, and advanced numerical modelling codes for coupled coal mine strata, water and gas simulations, and longwall goaf gas ttow investigations. This integrated approach has resulted in significant insights into the complex dynamic imeraction between strata, groundwater, and gas during mining at Huainan Mining Group in recent years. Based on the lindings from the extensive field monitoring and numerical modelling studies, a three-dimensional annular-shaped over-lying zone along the perimeter of the longwall panel was identified for optimal methane drainage during mining.
基金the supports of the two scientific surveys made by Fenghui No 16 and Zhe Yunyu No 807funded by National Nature Science Foundation of China (NSFC 41276156)+5 种基金National High-tech R&D Program of China (863 Program 2012AA092303)Project of Shanghai science and technology innovation (12231203900)Industrialization program of National Development and Reform Commission (2159999)Shanghai Leading Academic Discipline Projectsupported by National Distant-water Fisheries Engineering Research Center
文摘The jumbo flying squid(Dosidicus gigas) population was surveyed with the help of Chinese squid jigging vessels off the Costa Rica Dome(4°–11°N, 90°–100°W) in 2009 and 2010. The daily catch of D. gigas in the two survey cruises ranged from 0 to 5.5 t and was mostly obtained from the areas bounded by 6°–9°N and 91°–94°W and by 6°30′–7°30′N and 96°–97°W. The sea surface temperature in the areas yielding the most catch ranged from 27.5 to 29℃. The sex ratio of the total catch was 3.75:1(female: male). The mantle length of the squid ranged from 211 to 355 mm(male) and from 204 to 429 mm(female) with an average of 297.9 and 306.7 mm, respectively. In the relationship of the mantle length(mm) and body weight(g) of the squid, there was no significant difference between sexes. The female and male were at a similar maturity, and most individuals are maturing or have matured with a few females being spent. The size(mantle length) and age at the first sexual maturity were 297 mm and 195 d in females, and less than 211 mm and 130 d in males, respectively. Most of the sampled stomachs(70.6%) had no food remains. The major preys of the squids were fish, cephalopods and crustaceans, with the most abundant Myctophum orientale and D. gigas. The preys in more than 65% of the non-empty sampled stomachs evidenced the cannibalism of D. gigas. The results improved current understanding of the fishery biology of D. gigas off the Costa Rica Dome, which may facilitate the assessment and management of relative fishery resources.
文摘Myoglobin has important biological functions in storing and transporting small diatomic molecules in human body. Two possible orientations of carbon monoxide (CO) in the heme distal pocket (named as BI and B2 states) of myoglobin have been experimentally indicated. In this study, ab initio quantum mechanics/molecular mechanics (QM/MM) molecular dynamics simulation of CO in myoglobin was carried out to investigate the two possible B states. Our results demonstrate that the B1 and B2 states correspond to Fe... CO (with carbon atom closer to iron center of heme) and Fe... OC (with oxygen atom closer to Fe), by comparing with the experimental infrared spectrum. QM electrostatic polarization effect on CO brought from the protein and solvent environment is the main driving force, which anchors CO in two distinctive orientations and hinders its rotation. The calculated vibrational frequency shift between the state B1 and B2 is 13.1 cm-1, which is in good agreement with experimental value of 11.5 cm-1. This study also shows that the electric field produced by the solvent plays an important role in assisting protein functions by exerting directional electric field at the active site of the protein, From residue-based electric field decomposition, several residues were found to have most contributions to the total electric field at the CO center, including a few charged residues and three adjacent uncharged polar residues (namely, HIS64, ILE107, and PHE43). This study provides new physical insights on rational design of enzyme with higher electric field at the active site.
基金Project(51375119) supported by the National Natural Science Foundation of China
文摘Pre-knowledge of machined surface roughness is the key to improve whole machining efficiency and meanwhile reduce the expenditure in machining optical glass components.In order to predict the surface roughness in ultrasonic vibration assisted grinding of brittle materials,the surface morphologies of grinding wheel were obtained firstly in the present work,the grinding wheel model was developed and the abrasive trajectories in ultrasonic vibration assisted grinding were also investigated,the theoretical model for surface roughness was developed based on the above analysis.The prediction model was developed by using Gaussian processing regression(GPR)due to the influence of brittle fracture on machined surface roughness.In order to validate both the proposed theoretical and GPR models,32sets of experiments of ultrasonic vibration assisted grinding of BK7optical glass were carried out.Experimental results show that the average relative errors of the theoretical model and GPR prediction model are13.11%and8.12%,respectively.The GPR prediction results can match well with the experimental results.
基金National Natural Science Foundation of China under Grant Nos.10375017 and 10575029
文摘The neutral gauge boson BH with the mass of hundreds GeV is the lightest particle predicted by the littlest Higgs (LH) model, and such particle should be the first signal of the LH model at the planed ILC if it exists indeed. In this paper, we study some processes of the BH production associated with the fermion pair at the ILC, i.e., γγ→ ff^- BH. The studies show that the most promising processes to detect BH amongγγ→ ff^- BH are γγ→ l'^+l'^-BH (l' = e,μ), and they can produce the sufficient signals in most parameter space preferred by the electroweak precision data at the ILC. On the other hand, the signal produced via the certain BH decay modes is typical and such signal can be easily identified from the SM background. Therefore, BH, the lightest gauge boson in the LH model, would be detectable at the photon collider realized at the ILC.
基金The National Natural Science Foundation of China(No.8123003481271739+2 种基金81501453)the Special Program of Medical Science of Jiangsu Province(No.BL2013029)the Natural Science Foundation of Jiangsu Province(No.BK20141342)
文摘In order to classify the minimal hepatic encephalopathy (MHE) patients from healthy controls, the independent component analysis (ICA) is used to generate the default mode network (DMN) from resting-state functional magnetic resonance imaging (fMRI). Then a Bayesian voxel- wised method, graphical-model-based multivariate analysis (GAMMA), is used to explore the associations between abnormal functional integration within DMN and clinical variable. Without any prior knowledge, five machine learning methods, namely, support vector machines (SVMs), classification and regression trees ( CART ), logistic regression, the Bayesian network, and C4.5, are applied to the classification. The functional integration patterns were alternative within DMN, which have the power to predict MHE with an accuracy of 98%. The GAMMA method generating functional integration patterns within DMN can become a simple, objective, and common imaging biomarker for detecting MIIE and can serve as a supplement to the existing diagnostic methods.
文摘We report physicochemical characteristics of various kinds of liquid milk commercially available in Pakistan in comparison with those of fresh natural milk from animals. Milk samples were collected from local markets at Peshawar, Pakistan, and analyzed for their physical features, including moisture, total solids, specific gravity, conductivity, viscosity and titratable acidity (lactic acid equivalent), and chemical components and macro-minerals, including total protein, casein, lactose, ash and minerals (Na, K and Mg). These items were compared with the physicochemical characteristics of the fresh natural milk samples from buffalo, cow and goat. The results were also compared with reported nutritional quality of milk from various countries and World Health Organization (WHO) standards. We found that all the physical features and chemical components of commercially available milk in Pakistan markets meet WHO's requirements, except for Na, K, Ca and Mg, which are below the standards.
基金The National Natural Science Foundation of China(No.60972001)the Science and Technology Plan of Suzhou City(No.SS201223)
文摘An adaptive topology learning approach is proposed to learn the topology of a practical camera network in an unsupervised way. The nodes are modeled by the Gaussian mixture model. The connectivity between nodes is judged by their cross-correlation function, which is also used to calculate their transition time distribution. The mutual information of the connected node pair is employed for transition probability calculation. A false link eliminating approach is proposed, along with a topology updating strategy to improve the learned topology. A real monitoring system with five disjoint cameras is built for experiments. Comparative results with traditional methods show that the proposed method is more accurate in topology learning and is more robust to environmental changes.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10375017 and 10575029
文摘The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs (LH) model, we study the process e-γ → veW^-H and calculate the contributions of the LH model to the cross section of this process. The results show that in most of the parameter spaces preferred by the electroweak precision data, the value of the relative correction is larger than 10%. Such correction to the process e-γ →veW^-H is large enough to be detected via e-γ collisions in the future high energy linear e^+ e^- collider (ILC) experiment with the c.m. energy √s = 500 GeV and a yearly integrated luminosity £ = 100fb^-1, which will give an idea/way to test the model.
基金supported by the National Key R&D Program of China(No.2018AAA0100804)the Talent Project of Revitalization Liaoning(No.XLYC1907022)+5 种基金the Key R&D Projects of Liaoning Province(No.2020JH2/10100045)the Capacity Building of Civil Aviation Safety(No.TMSA1614)the Natural Science Foundation of Liaoning Province(No.2019-MS-251)the Scientific Research Project of Liaoning Provincial Department of Education(Nos.L201705,L201716)the High-Level Innovation Talent Project of Shenyang(No.RC190030)the Second Young and Middle-Aged Talents Support Program of Shenyang Aerospace University.
文摘Due to the influence of terrain structure,meteorological conditions and various factors,there are anomalous data in automatic dependent surveillance-broadcast(ADS-B)message.The ADS-B equipment can be used for positioning of general aviation aircraft.Aim to acquire the accurate position information of aircraft and detect anomaly data,the ADS-B anomaly data detection model based on deep learning and difference of Gaussian(DoG)approach is proposed.First,according to the characteristic of ADS-B data,the ADS-B position data are transformed into the coordinate system.And the origin of the coordinate system is set up as the take-off point.Then,based on the kinematic principle,the ADS-B anomaly data can be removed.Moreover,the details of the ADS-B position data can be got by the DoG approach.Finally,the long short-term memory(LSTM)neural network is used to optimize the recurrent neural network(RNN)with severe gradient reduction for processing ADS-B data.The position data of ADS-B are reconstructed by the sequence to sequence(seq2seq)model which is composed of LSTM neural network,and the reconstruction error is used to detect the anomalous data.Based on the real flight data of general aviation aircraft,the simulation results show that the anomaly data can be detected effectively by the proposed method of reconstructing ADS-B data with the seq2seq model,and its running time is reduced.Compared with the RNN,the accuracy of anomaly detection is increased by 2.7%.The performance of the proposed model is better than that of the traditional anomaly detection models.
基金The project supported in part by USA NIH Grant under HG002894
文摘The evolutionary dynamics first conceived by Darwin and Wallace, referring to as Darwinian dynamics in the present paper, has been found to be universally valid in biology. The statistical mechanics and thermodynamics, while enormous successful in physics, have been in an awkward situation of wanting a consistent dynamical understanding. Here we present from a formal point of view an exploration of the connection between thermodynamics and Darwinian dynamics and a few related topics. We first show that the stochasticity in Darwinian dynamics implies the existence temperature, hence the canonical distribution of Boltzmann-Gibbs type. In term of relative entropy the Second Law of thermodynamics is dynamically demonstrated without detailed balance condition, and is valid regardless of size of the system. In particular, the dynamical component responsible for breaking detailed balance condition does not contribute to the change of the relative entropy. Two types of stochastic dynamical equalities of current interest are explicitly discussed in the present approach: One is based on Feynman-Kac formula and another is a generalization of Einstein relation. Both are directly accessible to experimental tests. Our demonstration indicates that Darwinian dynamics represents logically a simple and straightforward starting point for statistical mechanics and thermodynamics and is complementary to and consistent with conservative dynamics that dominates the physical sciences. Present exploration suggests the existence of a unified stochastic dynamical framework both near and far from equilibrium.
文摘It is argued that it has not yet been able to value the historical, philosophical and epistemological travail, represented by the filth and fourth centuries BC of the ancient Greek world, which preceded the highest scientific heritage, represented by the so-called golden age of Euclid, Archimedes and Apollonius, Ⅲ-Ⅱ century BC. Well, it is believed that with our complex concept of tradition of thought within which we insert not only epistemological concepts but also philosophical principles, historical and social frameworks, in stasis or in strong movement, processed by us, it is possible better interpret that happy moment of scientific constructions of the third and second century BC, as a result of the valorization of the deep travail and serious battle that preceded it between the fourth and fifth century BC. It is investigated in particular in our paper the development of astronomical thought between the fifth and fourth centuries BC, in the ancient Greek thought, and at last a particular presumed criticism by Archimedes in his Sandreckoner to Aristarchus.
文摘Objective:To investigate the neural electrophysiologieal activity underlying Chinese and Eng- lish Stroop tasks for Chinese English bilinguals.Methods:Event-related potentials(ERPs)were recorded in 14 Chinese bilinguals with a moderate command of English when they performed the Stroop task pre- sented in English words and Chinese characters,respectively.Results:In Chinese task version,it was found an increased positivity over bilateral front-polar regions on incongruent trials compared with congru- ent trials,followed by an increased negativity over fronto-central region and an increased positivity over occipital region.While in English task version,only the increased negativity was observed over fronto-cen- tral region,but with reduced amplitude and anterior distribution.Conclusion:This increased negativity was proposed as an index of the resolution processes of conflicting information in the incongruent situa- tion.The increased positivity over occipital region on Chinese incongruent trials may indicate visually rechecking effect for Chinese character.
文摘Considering that thermodynarmic irreversibility and hydrodynamic equations can not be derived rigorously and unifiedly from the Liouville equations, the anomalous Langevin equation in the Liouville space is proposed as a fundamental equation of statistical physics. This equation reflects that the law of motion of particles obeying reversible, deterministic laws in dynamics becomes irreversible and stochastic in thermodynamics. From this the fundamental equations of nonequilibrium thermodynamics, the principle of entropy increase and the theorem of minimum entropy production have been derived. The hydrodynamic equations, such as the generalized Navier-Stokes equation and the mass drift-diffusion equation etc. have been derived rigorously from the kinetic kinetic equation which is reduced from the anomalous Langevin equation in Liouville space. All these are unified and self consistent. But it is difficult to prove that entropy production density σ can never be negative everywhere for all the isolated inhomogeneous systems far from equilibrium.