模态性质命题真值关系考察

本文通过构造四个逻辑关系示意图，全面刻画了模态性质命题及其否定形式之间所存在的12个等值式、12个矛盾式和120个蕴涵式，这些等值式、矛盾式和蕴涵式都与人们的实际思维密切联系，均可借助自然语言的实例得到直观理解，并在思维实践中加以运用。

模态性质命题传统逻辑方阵的建立

通过建立模态性质命题:模态A、模态E、模态I、模态O命题间的5个逻辑方阵,以及将模态单称命题:模态单称肯定命题(a)和模态单程否定命题(e)引入模态性质命题逻辑方阵,能够有效地涵盖模态性质命题推理的56个有效式,以及关于模态单称命题与模态A、模态E、模态I、模态O命题之间推理的48个有效式,从而有利于用传统逻辑的方法掌握繁多的模态性质命题间的关系及推理。

论事实与命题的同一——真理同一论的智识资源、核心论题及困境

真理同一论是当代真理论中一个非常显目的版本,根据这一理论,一个命题是真的,当且仅当它同一于某个事实。对同一论而言,命题与事实如何同一,这是它最核心的论题。在这一论题上,存在两种主要的策略,一是把命题推向事实,一是把事实推向命题。在运思这些策略时,同一论者猛烈抨击了真理符合论,认为命题与事实的关系不是符合而是同一。但是,由于通常认为命题属于涵义领域,事实属于指称领域,因此同一论的策略必定会面临严峻挑战。不仅如此,模态问题强有力地表明了,事实并不同一于命题。

Firmness evaluation of melon using its vibration characteristic and finite element analysis

The “Huang gua” melons were measured for their physical properties including firmness and static elastic modulus. The vibrational characteristics of fruits and vegetables are governed by their elastic modulus (firmness), mass, and geometry. Therefore, it is possible to evaluate firmness of fruits and vegetables based on their vibrational characteristics. Analysis of the vibration responses of a fruit is suggested for measuring elastic properties (Firmness) non-destructively. The impulse response method is often used to measure firmness of fruits. The fruit was excited using three types of balls (wooden, steel and rubber) and the vibration is detected by an accelerometer. The Instron device was used to measure the static elastic modulus of the inner, middle and outer portions of melon flesh. Finite element (FE) technique was used to determine the optimum excitation location of the chosen measurement sensor and to analyze the mode shape fruits. Four types of mode shapes (torsional or flexural mode shape, first-type, second-type spherical mode and breathing mode shape) were found. Finite element simulation results agreed well with experimental results. Correlation between the firmness and resonant frequency (r2=0.91) and between the resonant frequency and stiffness factor (r2=0.74) existed. The optimum location and suitable direction for excitation and response measurement on the fruit were suggested.

Dynamic phase-mining optimization in open-pit metal mines

Three important aspects of phase-mining must be optimized:the number of phases,the geometry and location of each phase-pit(including the ultimate pit),and the ore and waste quantities to be mined in each phase.A model is presented,in which a sequence of geologically optimum pits is first generated and then dynamically evaluated to simultaneously optimize the above three aspects,with the objective of maximizing the overall net present value.In this model,the dynamic nature of the problem is fully taken into account with respect to both time and space,and is robust in accommodating different pit wall slopes and different bench heights.The model is applied to a large deposit consisting of 2044 224 blocks and proved to be both efficient and practical.

Dynamic response law about gravity retaining wall to seismic characteristics and earth fill properties

In order to find the dynamic response laws of retaining walls affected by certain earthquake loads,the influence of the seismic wave characteristics and sub-grade fill parameters(including the foundation surface slope) were focused on,and a series of tests were performed.The results show that the maximum stress of the retaining wall decreases as internal friction angle,foundation slope,filled soil cohesion and the biggest dynamic elastic modulus increase,while it increases with the seismic frequency and seismic input peak dropping.The addition value of dynamics earth pressure increases when seismic frequency and seismic input peak are reduced,while it decreases when the filled soil cohesion and internal friction angle rise.Meanwhile,dynamic elastic modulus and foundation slope have no obvious influences on addition value of dynamics earth pressure.The slope will be instable if the seismic input peak exceeds 0.5g and be disruptive if seismic frequency is larger than 2.5 Hz.The mid-lower parts of retaining walls are in most heavy and obvious response to these factors,which reveals the mechanism of "belly burst" in retaining wall that appears commonly in practical projects.

Squeezing Properties of the Generalized Multimode Squeezed States

By means of the invariance of Weyl ordering under similar transformations we derive the explicit form of the generalized multimode squeezed states. Moreover, the completeness relation and the squeezing properties of the generalized multimode squeezed states are discussed.

Coordinate-Dependent Two-Mode Squeezing Transformations and the Corresponding Squeezed States

We introduce the coordinate-dependent two-mode squeezing transformations and discuss the properties of the corresponding two-mode squeezed states.

Gound State Properties of Nuclei in ^(295)118 α-Decay Chain

The properties of nuclei belonging to the α-decay chain of superheavy element ^295118 have been studied in the framework of axially deformed relativistic mean field （RMF） theory with the parameter set of NL-Z2 in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, and α-decay energies Qα have been obtained and agree well with those from finite-range droplet model （FRDM）. The single-particle spectra of nuclei in ^295118 α-decay chain show that the shell gaps present obviously nucleon number dependence. The root-mean-square （rms） radii of proton, neutron and matter distributions change slowly from ^283112 to ^295118 but dramatically from ^279110 to ^283112, which may be due to the subshell closure at Z = 110 in ^279110. The α-decay half-lives in 295118 decay chain are evaluated by employing the cluster model and the generalized liquid drop model （GLDM）, and the overall agreement is found when they are compared with the known experimental data. The α-decay lifetimes obtained from the cluster model are slightly larger than those of GLDM ones. Finally, we predict the α-decay half-lives of Z=118, 116, 114, 112 isotopes using the cluster model and GLDM, which also indicate these two models can corroborate each other in studies on superheavy nuclei. The results from GLDM are always lower than those obtained from the cluster model.

Sensitivity analysis of influencing parameters in cavern stability

In order to analyze the stability of the underground rock structures,knowing the sensitivity of geomechanical parameters is important.To investigate the priority of these geomechanical properties in the stability of cavern,a sensitivity analysis has been performed on a single cavern in various rock mass qualities according to RMR using Phase 2.The stability of cavern has been studied by investigating the side wall deformation.Results showed that most sensitive properties are coefficient of lateral stress and modulus of deformation.Also parameters of Hoek-Brown criterion and r c have no sensitivity when cavern is in a perfect elastic state.But in an elasto-plastic state,parameters of Hoek-Brown criterion and r c affect the deformability;such effect becomes more remarkable with increasing plastic area.Other parameters have different sensitivities concerning rock mass quality(RMR).Results have been used to propose the best set of parameters for study on prediction of sidewall displacement.

Quantum Properties of Two-Mode Squeezed Even and Odd Coherent States

Two new types of quantum states are constructed by applying the operator s（ξ） = exp（ξ＊ ab - ξa＋b＋） on the two-mode even and odd coherent states. The mathematical and quantum statistical properties of such states are investigated. Various nonclassical features of these states, such as squeezing properties, the inter-mode photon bunching, and the violation of Cauchy-Schwarz inequality, are discussed. The Wigner function in these states are studied in detail.

Analysis of a mutualism model with stochastic perturbations

This paper is concerned with a mutualism ecological model with stochastic perturba- tions. The local existence and uniqueness of a positive solution are obtained with positive initial value, and the asymptotic behavior to the problem is studied. Moreover, we show that the solution is stochastically bounded, uniformly continuous and stochastic perma- nence. The sufficient conditions for the system to be extinct are given and the conditionsfor the system to be persistent are also established. At last, some figures are presented to illustrate our main results.

Development of solid-state nanopore fabrication technologies

As the key components of nanopore-based nucleic acid sequencing systems, nanopores have drawn more and more scientific interests over these years. Although most of the early nanopore-based sequencers adopted biological nanopores, solid-state nanopores have been gradually growing in popularity due to their increased robustness and durability, control over pore geometry and surface properties, as well as compatibility with the existing semiconductor and microfiuidics fabrication techniques. Besides acting as a platform for biomolecular analysis, solid-state nanopores also have great potential in many other fields such as near-field optics, nanostencil lithography and ionic logic circuitry, due to the possibility of parallel massive production. Therefore, many approaches for the fabrication of solid-state nanopores have been developed. This paper reviews the typical solid-state nanopore fabrication techniques reported to date and compares their advantages and disadvantages. The specific applications of each kind of solid-state nanopores are also summarized based on the carefully analysis of their unique morphologies and properties such as the feature size, inner structure and possibility of massive production.

Topological flat bands in twisted trilayer graphene

Twisted trilayer graphene(TLG)may be the simplest realistic system so far,which has flat bands with nontrivial topology.Here,we give a comprehensive calculation about its band structures and the band topology,i.e.,valley Chern number of the nearly flat bands,with the continuum model.With realistic parameters,the magic angle of twisted TLG is about 1.12°,at which two nearly flat bands appears.Unlike the twisted bilayer graphene,a small twist angle can induce a tiny gap at all the Dirac points,which can be enlarged further by a perpendicular electric field.The valley Chern numbers of the two nearly flat bands in the twisted TLG depends on the twist angleθand the perpendicular electric field E⊥.Considering its topological flat bands,the twisted TLG should be an ideal experimental platform to study the strongly correlated physics in topologically nontrivial flat band systems.And,due to its reduced symmetry,the correlated states in twisted TLG should be quite different from that in twisted bilayer graphene and twisted double bilayer graphene.

Matrix Product State, Quantum Entanglement, and Criticality in the One-Dimensional Dimerized Antiferromagnetic Heisenberg Model

The matrix product state （MPS） is utilized to investigate the ground state properties and quantum phase transitions （OPTs） of the dimerized antiferromagnetic Heisenberg （DAH） model. The ground state MPS wavefunctions determined by the infinite time-evolving block decimation （iTEBD） algorithm are shown to be very efficient descriptions of DAH model. In the thermodynamic limit, the quantum entanglement, the bond energy~ and the nearest-neighbor correlations are calculated. It is revealed that the singular behavior of the bipartite entanglement can detect the QPTs directly. The critical point J2c= 1.0 is determined evidently, and the quantum phase transition is argued to belong to the second-order category. At the critical point, logarithmic divergent character of the block entanglement is observed, and the system can be described by a free bosonic field theory.