Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix...Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix elements from a dual fermion-boson Lagrangian. In this formalism, the fermion binding energies are compensated by boson energies, indicating that particles can be generated out of the vacuum. This yields quantitative solutions for various mesons ω (0.78 GeV) - Υ (9.46 GeV) and all leptons e, μ and τ, with uncertainties in the extracted properties of less than 1‰. For transparency, a Web-page with the address htpps://h2909473.stratoserver.net has been constructed, where all calculations can be run on line and also the underlying fortran source code can be inspected.展开更多
A bound state formalism derived from a fermion-boson symmetric Lagrangian has been used to calculate the nucleon masses, the charge neutrality of the neutron, the magnetic moments and the electromagnetic form factor r...A bound state formalism derived from a fermion-boson symmetric Lagrangian has been used to calculate the nucleon masses, the charge neutrality of the neutron, the magnetic moments and the electromagnetic form factor ratios μpGEp/GMpand μnGEn/GMn. A quantitative description is obtained, assuming a mixing of a scalar bound state of 3(f f¯)fstructure with its corresponding vector (f f¯)fstate (f indicating massless elementary fermions). Only a few parameters are needed, mainly fixed by energy and momentum conservation. The nucleon stability is explained by an extra binding in the confinement potential, negative for electric and positive for magnetic binding of the proton, and opposite for the neutron. The stronger electric extra binding of the proton allows a decay of the neutron to proton and electron.展开更多
The massive vector bosons Z o, W ± and the scalar Higgs-boson H o assumed in weak interaction theory, but also the six quarks required in strong interactions are well understood in an alternative quantum field th...The massive vector bosons Z o, W ± and the scalar Higgs-boson H o assumed in weak interaction theory, but also the six quarks required in strong interactions are well understood in an alternative quantum field theory of fermions and bosons: Z o and W ± as well as all quark-antiquark states (here only the tt¯state is discussed) are described by bound states with scalar coupling between their massless constituents and have a structure similar to leptons. However, the scalar Higgs-boson H o corresponds to a state with vector coupling between the elementary constituents. Similar scalar states are expected also in the mass region of the mesons ω (0.782 GeV) - Υ ( 9.46 GeV). The underlying calculations can be run on line using the Web-address https://h2909473.stratoserver.net.展开更多
The National Development and Reform Commission(NDRC)recently characterizedthe investment developments of this year’s first two months as"rapid,stable andmoderate."China’s investment in these two months tot...The National Development and Reform Commission(NDRC)recently characterizedthe investment developments of this year’s first two months as"rapid,stable andmoderate."China’s investment in these two months totaled RMB653.5 billion,a yearlygrowth of 23.4%,compared With 24.5% in the same period of 2006.The展开更多
The U.S.Department of Health and Human Services convened the 2018 Physical Activity Guidelines Advisory Committee(PAGAC)and charged it with reviewing and summarizing the current scientific evidence linking physical ac...The U.S.Department of Health and Human Services convened the 2018 Physical Activity Guidelines Advisory Committee(PAGAC)and charged it with reviewing and summarizing the current scientific evidence linking physical activity to human health and function.The 2018 PAGAC Scientific Report1 serves as the basis for the Physical Activity Guidelines for Americans,2nd edition3 The 2018 Scientific Report extends the findings of the 2008 Scientific Report3 by examining a broader range of health outcomes and special populations that benefit from increased physical activity.In addition,the 2018 Scientific Report more closely examined the specific types,volumes,and intensities of physical activity that are associated with those benefits and now describes novel strategies for physical activity promotion at the population level.展开更多
Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationshi...Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationship(QSAR) models of the bioconcentration factors(BCF) of the anilines in fish were established using some of the following calculated descriptors: EHOMO, ENHOMO, ELUMO, ENLUMO, ΔE1(= ELUMO- EHOMO), ΔE2(= ENLUMO- ENHOMO), dipole moment(μ), molecular volume(V), vibrational energy of 0 K(Ev), thermodynamic energy(E), heat capacity(Cv), entropy(Sm) and the charge of benzene ring(Qph). Using the variable selection and leaps-and-bounds regression, the quantum chemical descriptors derived directly from the molecular structures were employed to develop a linear QSAR model between the bioconcentration factors(BCF) and two descriptors(Sm, ENHOMO) of 12 chloroanilines. Statistically, the most significant one is a two-parameter linear equation with the correlation coefficient(R^2) of 0.981 and cross-validated correlation coefficient(Rcv^2) of 0.967. The established QSAR model has good stability and predictability based on the results from Rcv2 of leave-one-out cross-validation, AIC, FIT and tα/2. The quantum chemical analyses were performed from two aspects of frontier molecular orbital and entropy. The results show that two structural describers are crucial to the bioconcentration activity of chloroanilines.展开更多
The COVID-19 pandemic has posed a serious threat to global mental health.Multiple lines of evidence suggest that there is a varying yet considerable increase in mental health issues among the general population and vu...The COVID-19 pandemic has posed a serious threat to global mental health.Multiple lines of evidence suggest that there is a varying yet considerable increase in mental health issues among the general population and vulnerable groups.12 The aftermath is obscure and speculative from a social,economic,individual and public mental health perspective.Recently published studies support the existence of an emotional epidemic curve,describing a high probability of an increase in the burden of mental health issues in the post-pandemic era.34 Furthermore,previous major public health emergencies showed that more than half of the population devel-oped mental health problems and required mental health intervention.45 There is,therefore,an urgent need to reorganise existing mental health services to address the current unmet needs for mental health and to prepare for future challenges in the postpandemic era in terms of prevention and management.展开更多
Twenty-three temperate China species of Lachnum, Lachnum abnorme, L. angustum, L. brevipilosum, L. calosporum, L. calyculiforme, L. carneolum, L. ciliare, L. controversum, L. flavidulum, L. cf. fushanese, L. indicum, ...Twenty-three temperate China species of Lachnum, Lachnum abnorme, L. angustum, L. brevipilosum, L. calosporum, L. calyculiforme, L. carneolum, L. ciliare, L. controversum, L. flavidulum, L. cf. fushanese, L. indicum, L. kumaonicum, L. lushanese, L. minutum, L. montanum, L. cf. pteridophyllum, L. pygmaeum, L. sclerotii var. sclerotii, L. sclerotii var. sichuanense, L. subpygmeaum, L. tenuissimum, L. virgineum and L. willisii are reported, whose main characteristics are given in a formula of the described species, some of which are discussed below.展开更多
Our knowledge of renal cell carcinoma(RCC) is rapidly expanding. For those who diagnose and treat RCC, it is important to understand the new developments. In recent years, many new renal tumors have been described and...Our knowledge of renal cell carcinoma(RCC) is rapidly expanding. For those who diagnose and treat RCC, it is important to understand the new developments. In recent years, many new renal tumors have been described and defined, and our understanding of the biology and clinical correlates of these tumors is changing. Evolving concepts in Xp11 translocation carcinoma, mucinous tubular and spindle cell carcinoma, multilocular cystic clear cell RCC, and carcinoma associated with neuroblastoma are addressed within this review. Tubulocystic carcinoma, thyroid-like follicular carcinoma of kidney, acquired cystic disease-associated RCC, and clear cell papillary RCC are also described. Finally, candidate entities, including RCC with t(6;11) translocation, hybrid oncocytoma/chromophobe RCC, hereditary leiomyomatosis and RCC syndrome, and renal angiomyoadenomatous tumor are reviewed. Knowledge of these new entities is important for diagnosis, treatment and subsequent prognosis. This review provides a targeted summary of new developments in RCC.展开更多
Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.Howev...Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.However,in the analysis of many data problems,it is more reasonable to select parts of objects which are useful to us or can meet the actual needs as a universe.Therefore,in order to make up for the deficiency of traditional models,a new model is introduced from the perspective of variable universe.Then,some interesting properties of this model,such as approximation sets,reduct of attributes and maximum part of universe,are discussed.Through the study of this paper,it can be seen that the model developed in our paper is not only more accurate but also more effective in describing uncertain knowledge.展开更多
A Quantitative Structure-activity Relationship(QSAR) model was developed to predict the hallucinogenic activity of phenylalkylamines by Artificial Neural Network(ANN) method.Each compound was represented by the ca...A Quantitative Structure-activity Relationship(QSAR) model was developed to predict the hallucinogenic activity of phenylalkylamines by Artificial Neural Network(ANN) method.Each compound was represented by the calculated structural descriptors involving constitutional,topological,geometrical,electrostatic and quantum-chemical features of compound.The ANN method produced a nonlinear and seven-descriptor QSAR model with a standard error S = 0.0128 and a correlation coefficient R = 0.9752.The electronic properties of 75 phenylalkylamines were calculated with Gaussian 03 program at the DFT/B3LYP/6-311+G(d,p) level.The quantum chemical analyses were performed from two aspects of frontier molecular orbital and charge distribution.The results show that seven structural describers are crucial to the hallucinogenic activity of phenylalkylamines and that the para-and ortho-positions could be active sites acting as electron donors.展开更多
Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen's neural mass model(NMM) was initially proposed to...Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen's neural mass model(NMM) was initially proposed to study the origin of alpha oscillations.Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods.In this study,we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM.First,the sigmoid nonlinear function in the NMM is approximated by its describing function,allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part.Second,by conducting a theoretical analysis,we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and,furthermore,accurately determine its amplitude and frequency.The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations.Furthermore,strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations.展开更多
The evolution of a pure coherent state into a chaotic state is described very well by a master equation, as is validated via an examination of the coherent state's evolution during the diffusion process, fully utiliz...The evolution of a pure coherent state into a chaotic state is described very well by a master equation, as is validated via an examination of the coherent state's evolution during the diffusion process, fully utilizing the technique of integration within an ordered product (IWOP) of operators. The same equation also describes a limitation that maintains the coherence in a weak diffusion process, i.e., when the dissipation is very weak and the initial average photon number is large. This equation is dp/dt = -κ[a+ap -a+pa -apa+ + paa+]. The physical difference between this diffusion equation and the better-known amplitude damping master equation is pointed out.展开更多
A robust controller method for flexible joint robot considering the effect caused by nonlinear friction was presented.The nonlinear friction was denoted as inverse additive output uncertainty relative to the nominal m...A robust controller method for flexible joint robot considering the effect caused by nonlinear friction was presented.The nonlinear friction was denoted as inverse additive output uncertainty relative to the nominal model in our work,based on which the describing function was analyzed in frequency domain,and the weighting function of nonlinear friction was further calculated as well. By combining the friction uncertainty,the mixed sensitivity H∞optimization was proposed as the benchmark for controller design, which also leaded to good performance of robustness. Furthermore,unstructured perturbation to the system was analyzed so that the stability was guaranteed. Simulation results show that the proposed controller can provide excellent tracking and regulation performance.展开更多
This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian traditi...This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian tradition of folklore stylistics. While addressing the representations of Biblical female characters, such as the Holy Virgin Mary Magdalene, the Heavenly Bride, and the Whore of Babylon, along with the portrayals of Doukhobor and other women, the paper identifies stylistic features in their textual descriptions. The study establishes connections between Doukhobor texts and Russian folklore and liturgical tradition. The paper strives to identify the place of Doukhobor psalms as an integral part of the Russian literary and folklore heritage展开更多
The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase character...The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase characteristics which are closely related to the phase difference of the sea clutter and the Doppler properties, are analyzed in detail based on the experimental data, recorded by the Mc Master University IPIX radar in 1993. That the phase term of the complex correlation presents linear change means that there exists the linearity of phase differences between different time intervals in the X-band sea clutter. This investigation explores the regularities about the effect of wind on the complex correlation with similar patterns for different polarization modes. The regularities indicate that the wind direction can be inferred from the distribution pattern of the complex correlation. Moreover, a model describing the relationships between the statistics of the complex correlation and wind parameters is proposed. The application for target detection based on the differences of characteristics of complex correlations between the sea clutter and the target are also investigated and the proposed features have been confirmed. The principle of the method is fundamental for broader future applications.展开更多
The paper searched for raw data about wild-caught fish, where a sigmoidal growth function described the mass growth significantly better than non-sigmoidal functions. Specifically, von Bertalanffy’s sigmoidal growth ...The paper searched for raw data about wild-caught fish, where a sigmoidal growth function described the mass growth significantly better than non-sigmoidal functions. Specifically, von Bertalanffy’s sigmoidal growth function (metabolic exponent-pair a = 2/3, b = 1) was compared with unbounded linear growth and with bounded exponential growth using the Akaike information criterion. Thereby the maximum likelihood fits were compared, assuming a lognormal distribution of mass (i.e. a higher variance for heavier animals). Starting from 70+ size-at-age data, the paper focused on 15 data coming from large datasets. Of them, six data with 400 - 20,000 data-points were suitable for sigmoidal growth modeling. For these, a custom-made optimization tool identified the best fitting growth function from the general von Bertalanffy-Pütter class of models. This class generalizes the well-known models of Verhulst (logistic growth), Gompertz and von Bertalanffy. Whereas the best-fitting models varied widely, their exponent-pairs displayed a remarkable pattern, as their difference was close to 1/3 (example: von Bertalanffy exponent-pair). This defined a new class of models, for which the paper provided a biological motivation that relates growth to food consumption.展开更多
At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myo...At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myopia illness to provide the theory foundation for researches on and preventions from myopia illness.We provide the mathematial model on describing the poor eyesight of the students after analysing thedeveloping lows of the poor eyesight of the students as follows:where p(r,t) is the student’s myopia falling ill rate function at time t and age r, u(r) denotes the initial stagemyopia falling ill rate function and v(t), the baby myopia falling ill rate function. It is a first order quasi-展开更多
The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a si...The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a single-cavitymultiple-device harmonic oscillator(SCMDHO).By means of describing the functions ofnonlinearity of Gunn diodes,the performances of the SCMDHO are analyzed.It is foundthat the voltage amplitudes are similar to those of SDHO,and the ratio of maximum pow-er of harmonic to that of fundamental is identical to that in SDHO when the devices havesame parameters.The harmonic injection locking behavior is also investigated.The injec-tion locking range is greater than that of SDHO if locking gain remains constant.A2-Gunn diode harmonic oscillator was designed.It delivers 30mW output power at103GHz.The mechanical tuning range is 4.15GHz when the output power remains morethan 10mW.The desired operation mode is stable.展开更多
文摘Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix elements from a dual fermion-boson Lagrangian. In this formalism, the fermion binding energies are compensated by boson energies, indicating that particles can be generated out of the vacuum. This yields quantitative solutions for various mesons ω (0.78 GeV) - Υ (9.46 GeV) and all leptons e, μ and τ, with uncertainties in the extracted properties of less than 1‰. For transparency, a Web-page with the address htpps://h2909473.stratoserver.net has been constructed, where all calculations can be run on line and also the underlying fortran source code can be inspected.
文摘A bound state formalism derived from a fermion-boson symmetric Lagrangian has been used to calculate the nucleon masses, the charge neutrality of the neutron, the magnetic moments and the electromagnetic form factor ratios μpGEp/GMpand μnGEn/GMn. A quantitative description is obtained, assuming a mixing of a scalar bound state of 3(f f¯)fstructure with its corresponding vector (f f¯)fstate (f indicating massless elementary fermions). Only a few parameters are needed, mainly fixed by energy and momentum conservation. The nucleon stability is explained by an extra binding in the confinement potential, negative for electric and positive for magnetic binding of the proton, and opposite for the neutron. The stronger electric extra binding of the proton allows a decay of the neutron to proton and electron.
文摘The massive vector bosons Z o, W ± and the scalar Higgs-boson H o assumed in weak interaction theory, but also the six quarks required in strong interactions are well understood in an alternative quantum field theory of fermions and bosons: Z o and W ± as well as all quark-antiquark states (here only the tt¯state is discussed) are described by bound states with scalar coupling between their massless constituents and have a structure similar to leptons. However, the scalar Higgs-boson H o corresponds to a state with vector coupling between the elementary constituents. Similar scalar states are expected also in the mass region of the mesons ω (0.782 GeV) - Υ ( 9.46 GeV). The underlying calculations can be run on line using the Web-address https://h2909473.stratoserver.net.
文摘The National Development and Reform Commission(NDRC)recently characterizedthe investment developments of this year’s first two months as"rapid,stable andmoderate."China’s investment in these two months totaled RMB653.5 billion,a yearlygrowth of 23.4%,compared With 24.5% in the same period of 2006.The
文摘The U.S.Department of Health and Human Services convened the 2018 Physical Activity Guidelines Advisory Committee(PAGAC)and charged it with reviewing and summarizing the current scientific evidence linking physical activity to human health and function.The 2018 PAGAC Scientific Report1 serves as the basis for the Physical Activity Guidelines for Americans,2nd edition3 The 2018 Scientific Report extends the findings of the 2008 Scientific Report3 by examining a broader range of health outcomes and special populations that benefit from increased physical activity.In addition,the 2018 Scientific Report more closely examined the specific types,volumes,and intensities of physical activity that are associated with those benefits and now describes novel strategies for physical activity promotion at the population level.
基金co-financed by the National Natural Science Foundation of China(21075138)special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(13K02ESPCT)
文摘Density functional theory(DFT)-B3LYP level with the 6-311G**(d,p) basis set was used to calculate a set of molecular quantum chemical descriptors of 12 chloroanilines. Quantitative structure-activity relationship(QSAR) models of the bioconcentration factors(BCF) of the anilines in fish were established using some of the following calculated descriptors: EHOMO, ENHOMO, ELUMO, ENLUMO, ΔE1(= ELUMO- EHOMO), ΔE2(= ENLUMO- ENHOMO), dipole moment(μ), molecular volume(V), vibrational energy of 0 K(Ev), thermodynamic energy(E), heat capacity(Cv), entropy(Sm) and the charge of benzene ring(Qph). Using the variable selection and leaps-and-bounds regression, the quantum chemical descriptors derived directly from the molecular structures were employed to develop a linear QSAR model between the bioconcentration factors(BCF) and two descriptors(Sm, ENHOMO) of 12 chloroanilines. Statistically, the most significant one is a two-parameter linear equation with the correlation coefficient(R^2) of 0.981 and cross-validated correlation coefficient(Rcv^2) of 0.967. The established QSAR model has good stability and predictability based on the results from Rcv2 of leave-one-out cross-validation, AIC, FIT and tα/2. The quantum chemical analyses were performed from two aspects of frontier molecular orbital and entropy. The results show that two structural describers are crucial to the bioconcentration activity of chloroanilines.
文摘The COVID-19 pandemic has posed a serious threat to global mental health.Multiple lines of evidence suggest that there is a varying yet considerable increase in mental health issues among the general population and vulnerable groups.12 The aftermath is obscure and speculative from a social,economic,individual and public mental health perspective.Recently published studies support the existence of an emotional epidemic curve,describing a high probability of an increase in the burden of mental health issues in the post-pandemic era.34 Furthermore,previous major public health emergencies showed that more than half of the population devel-oped mental health problems and required mental health intervention.45 There is,therefore,an urgent need to reorganise existing mental health services to address the current unmet needs for mental health and to prepare for future challenges in the postpandemic era in terms of prevention and management.
基金Project supported by the Natural Science Foundation of AnhuiProvince (No. 050430502) and Education Department of AnhuiProvince (No. 2004kj045), China
文摘Twenty-three temperate China species of Lachnum, Lachnum abnorme, L. angustum, L. brevipilosum, L. calosporum, L. calyculiforme, L. carneolum, L. ciliare, L. controversum, L. flavidulum, L. cf. fushanese, L. indicum, L. kumaonicum, L. lushanese, L. minutum, L. montanum, L. cf. pteridophyllum, L. pygmaeum, L. sclerotii var. sclerotii, L. sclerotii var. sichuanense, L. subpygmeaum, L. tenuissimum, L. virgineum and L. willisii are reported, whose main characteristics are given in a formula of the described species, some of which are discussed below.
文摘Our knowledge of renal cell carcinoma(RCC) is rapidly expanding. For those who diagnose and treat RCC, it is important to understand the new developments. In recent years, many new renal tumors have been described and defined, and our understanding of the biology and clinical correlates of these tumors is changing. Evolving concepts in Xp11 translocation carcinoma, mucinous tubular and spindle cell carcinoma, multilocular cystic clear cell RCC, and carcinoma associated with neuroblastoma are addressed within this review. Tubulocystic carcinoma, thyroid-like follicular carcinoma of kidney, acquired cystic disease-associated RCC, and clear cell papillary RCC are also described. Finally, candidate entities, including RCC with t(6;11) translocation, hybrid oncocytoma/chromophobe RCC, hereditary leiomyomatosis and RCC syndrome, and renal angiomyoadenomatous tumor are reviewed. Knowledge of these new entities is important for diagnosis, treatment and subsequent prognosis. This review provides a targeted summary of new developments in RCC.
基金supported by the National Natural Science Foundation of China(Nos.61976254,61772002)the Natural Science Foundation of Fujian Province(No.2020J01707)National Fund Cultivation program of Jimei University(No.ZP2020056).
文摘Rough set theory has a very good effect in information processing and knowledge discovery.In an information table,the current scholars regard all objects as a universe,and then establish various rough set models.However,in the analysis of many data problems,it is more reasonable to select parts of objects which are useful to us or can meet the actual needs as a universe.Therefore,in order to make up for the deficiency of traditional models,a new model is introduced from the perspective of variable universe.Then,some interesting properties of this model,such as approximation sets,reduct of attributes and maximum part of universe,are discussed.Through the study of this paper,it can be seen that the model developed in our paper is not only more accurate but also more effective in describing uncertain knowledge.
基金supported by the Natural Science Foundation of Shanxi Province (2007011025)
文摘A Quantitative Structure-activity Relationship(QSAR) model was developed to predict the hallucinogenic activity of phenylalkylamines by Artificial Neural Network(ANN) method.Each compound was represented by the calculated structural descriptors involving constitutional,topological,geometrical,electrostatic and quantum-chemical features of compound.The ANN method produced a nonlinear and seven-descriptor QSAR model with a standard error S = 0.0128 and a correlation coefficient R = 0.9752.The electronic properties of 75 phenylalkylamines were calculated with Gaussian 03 program at the DFT/B3LYP/6-311+G(d,p) level.The quantum chemical analyses were performed from two aspects of frontier molecular orbital and charge distribution.The results show that seven structural describers are crucial to the hallucinogenic activity of phenylalkylamines and that the para-and ortho-positions could be active sites acting as electron donors.
基金Project supported by the National Natural Science Foundation of China(Grant No.61473208)the Tianjin Research Program of Application Foundation and Advanced Technology,China(Grant No.15JCYBJC47700)+1 种基金the National Institutes of Health,USA(Grant Nos.R01DA040990 and R01EY027544)the Project of Humanities and Social Sciences from the Ministry of Education,China(Grant No.17YJAZH092)
文摘Spontaneous alpha oscillations are a ubiquitous phenomenon in the brain and play a key role in neural information processing and various cognitive functions.Jansen's neural mass model(NMM) was initially proposed to study the origin of alpha oscillations.Most of previous studies of the spontaneous alpha oscillations in the NMM were conducted using numerical methods.In this study,we aim to propose an analytical approach using the describing function method to elucidate the spontaneous alpha oscillation mechanism in the NMM.First,the sigmoid nonlinear function in the NMM is approximated by its describing function,allowing us to reformulate the NMM and derive its standard form composed of one nonlinear part and one linear part.Second,by conducting a theoretical analysis,we can assess whether or not the spontaneous alpha oscillation would occur in the NMM and,furthermore,accurately determine its amplitude and frequency.The results reveal analytically that the interaction between linearity and nonlinearity of the NMM plays a key role in generating the spontaneous alpha oscillations.Furthermore,strong nonlinearity and large linear strength are required to generate the spontaneous alpha oscillations.
基金Project supported by the National Basic Research Program of China(Grant No.2012CB922103)the National Natural Science Foundation of China(GrantNos.11175113 and 11274104)the Natural Science Foundation of Hubei Province of China(Grant No.2011CDA021)
文摘The evolution of a pure coherent state into a chaotic state is described very well by a master equation, as is validated via an examination of the coherent state's evolution during the diffusion process, fully utilizing the technique of integration within an ordered product (IWOP) of operators. The same equation also describes a limitation that maintains the coherence in a weak diffusion process, i.e., when the dissipation is very weak and the initial average photon number is large. This equation is dp/dt = -κ[a+ap -a+pa -apa+ + paa+]. The physical difference between this diffusion equation and the better-known amplitude damping master equation is pointed out.
基金National Natural Science Foundation of China(No.61273339)
文摘A robust controller method for flexible joint robot considering the effect caused by nonlinear friction was presented.The nonlinear friction was denoted as inverse additive output uncertainty relative to the nominal model in our work,based on which the describing function was analyzed in frequency domain,and the weighting function of nonlinear friction was further calculated as well. By combining the friction uncertainty,the mixed sensitivity H∞optimization was proposed as the benchmark for controller design, which also leaded to good performance of robustness. Furthermore,unstructured perturbation to the system was analyzed so that the stability was guaranteed. Simulation results show that the proposed controller can provide excellent tracking and regulation performance.
文摘This paper analyzes the language employed in the representations of women in Doukhobor Russian ritual texts called "ncanMbf' (psalms) from the viewpoint of linguistic text analysis performed in the Russian tradition of folklore stylistics. While addressing the representations of Biblical female characters, such as the Holy Virgin Mary Magdalene, the Heavenly Bride, and the Whore of Babylon, along with the portrayals of Doukhobor and other women, the paper identifies stylistic features in their textual descriptions. The study establishes connections between Doukhobor texts and Russian folklore and liturgical tradition. The paper strives to identify the place of Doukhobor psalms as an integral part of the Russian literary and folklore heritage
基金supported by the National Natural Science Foundation of China (61271406)
文摘The correlation analysis of sea clutter data in a complex domain is conducted in this study. Specific to X-band sea clutter, the statistical characteristics of the complex correlation, particularly the phase characteristics which are closely related to the phase difference of the sea clutter and the Doppler properties, are analyzed in detail based on the experimental data, recorded by the Mc Master University IPIX radar in 1993. That the phase term of the complex correlation presents linear change means that there exists the linearity of phase differences between different time intervals in the X-band sea clutter. This investigation explores the regularities about the effect of wind on the complex correlation with similar patterns for different polarization modes. The regularities indicate that the wind direction can be inferred from the distribution pattern of the complex correlation. Moreover, a model describing the relationships between the statistics of the complex correlation and wind parameters is proposed. The application for target detection based on the differences of characteristics of complex correlations between the sea clutter and the target are also investigated and the proposed features have been confirmed. The principle of the method is fundamental for broader future applications.
文摘The paper searched for raw data about wild-caught fish, where a sigmoidal growth function described the mass growth significantly better than non-sigmoidal functions. Specifically, von Bertalanffy’s sigmoidal growth function (metabolic exponent-pair a = 2/3, b = 1) was compared with unbounded linear growth and with bounded exponential growth using the Akaike information criterion. Thereby the maximum likelihood fits were compared, assuming a lognormal distribution of mass (i.e. a higher variance for heavier animals). Starting from 70+ size-at-age data, the paper focused on 15 data coming from large datasets. Of them, six data with 400 - 20,000 data-points were suitable for sigmoidal growth modeling. For these, a custom-made optimization tool identified the best fitting growth function from the general von Bertalanffy-Pütter class of models. This class generalizes the well-known models of Verhulst (logistic growth), Gompertz and von Bertalanffy. Whereas the best-fitting models varied widely, their exponent-pairs displayed a remarkable pattern, as their difference was close to 1/3 (example: von Bertalanffy exponent-pair). This defined a new class of models, for which the paper provided a biological motivation that relates growth to food consumption.
文摘At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myopia illness to provide the theory foundation for researches on and preventions from myopia illness.We provide the mathematial model on describing the poor eyesight of the students after analysing thedeveloping lows of the poor eyesight of the students as follows:where p(r,t) is the student’s myopia falling ill rate function at time t and age r, u(r) denotes the initial stagemyopia falling ill rate function and v(t), the baby myopia falling ill rate function. It is a first order quasi-
基金The Project Supported by National Science Foundation of China
文摘The equivalent circuit of single-cavity multiple-device fundamentaloscillator(SCMDFO)and that of single-device harmonic oscillator(SDHO)proposed byK.Kurokawa and K.Solbach,respectively,are extended and applied to a single-cavitymultiple-device harmonic oscillator(SCMDHO).By means of describing the functions ofnonlinearity of Gunn diodes,the performances of the SCMDHO are analyzed.It is foundthat the voltage amplitudes are similar to those of SDHO,and the ratio of maximum pow-er of harmonic to that of fundamental is identical to that in SDHO when the devices havesame parameters.The harmonic injection locking behavior is also investigated.The injec-tion locking range is greater than that of SDHO if locking gain remains constant.A2-Gunn diode harmonic oscillator was designed.It delivers 30mW output power at103GHz.The mechanical tuning range is 4.15GHz when the output power remains morethan 10mW.The desired operation mode is stable.