“半”状态——当代视觉艺术设计方式的思考

对于全世界艺术史的发展而言,可以看出任何一个时代的艺术都与生活密切相关,艺术设计满足人们对于生活的所有想象。随着时代的不断发展,媒体技术越来越发达,图像时代的到来,使人们对于艺术有了新的理解,视觉的艺术在整体表现形式上会涉及到多种感官的需求,通常情况下,视觉艺术还会与文学、音乐等艺术形式进行结合,以此来达到更加完美的效果。当今社会的艺术形式以及内容的变动是以流动性为主要特征的,艺术的表现形式已经不再局限于一个单一的个体,并且艺术的边界分化也变得越来越模糊,多种形式进行融合,从而在很大程度上渲染了艺术的整体效果以及表现力。'半'在我国古代所指的是一种适度的文化艺术表现形式,在当代的视觉艺术当中,'半'更多的被当成不强求的艺术表现,有一种随遇而安的坦然情结,这也是当代艺术中的一个缩影。本文针对在此状态下的当代视觉艺术设计方式进行了思考,并且给出了自己的看法。

Semi-solid near-net shape rheocasting of heat treatable wrought aluminum alloys

Flexibility of the CSIR-RCS, induction stirring with simultaneous air cooling process, in combination with high pressure die casting is successfully demonstrated by semi-solid rheocasting of plates performed on commercial 2024, 6082 and 7075 wrought aluminum alloys. Tensile properties were measured for the above mentioned rheocast wrought aluminum alloys in the T6 condition. The results showed that tensile properties were close to or even in some cases exceeded the minimum specifications. The yield strength and elongation of rheocast 2024-T6 exceeded the minimum requirements of the wrought alloy in the T6 condition but the ultimate tensile strength achieved only 90% of the specification because the Mg content of the starting alloy was below the commercial alloy specification. The strengths of rheocast 6082-T6 exceeded all of the wrought alloy T6 strength targets but the elongation only managed 36% of the required minimum due to porosity, caused by incipient melting during solution heat treatment, and the presence of fine intermetallie needles in the eutectic. The yield strength of rheocast 7075 exceeded the required one and the ultimate tensile strength also managed 97% of the specification; while the elongation only reached 46% of the minimum requirement also due to incipient melting porosity caused during the solution heat treatment process.

Effects of rheoforming on microstructures and mechanical properties of 7075 wrought aluminum alloy

It is economically advantageous to cast wrought aluminum alloys directly into near-net-shape components.The objective of the present work is to take advantage of the rheoforming with 7075 alloy to improve the competitiveness of this emerging technology in the manufacture of wrought aluminum alloy.High quality semi-solid slurry was produced,in which primary α(Al) presents in diameter of 62 μm and shape factor of 0.78 and features no eutectics entrapped.Higher forming pressure results in small grain size,improved shape factor and higher density.Especially,rheoforming can effectively reduce the occurrence of hot tearing.The average yield strength and elongation of the rheoformed samples in the T6 condition are 483 MPa and 8%,respectively.

Optimal non-fragile controller realization algorithm and application to control problems

To reduce the fragility encountered in controller implementation, which is a measure of extent to describe small perturbations in controller parameters caused by rounding-off errors or component tolerances, and keep the system stability and performance, approaches of weighted eigenvalue sensitivity and stability radii comparison were used for computation and reduction of controller fragility. An algorithm has been derived for the efficient reduction of controller fragility, which used eigenstructure decomposition to obtain the suboptimal solution. The algorithm was tested for different control problems through reducing their fragility by a large margin. Different canonical forms were analyzed for fragility, including controllable canonical form, observable canonical form, modal canonical form, balanced realization and optimal (non-fragile) form. Different realizations were implemented through C language Matlab EXecutable (CMEX) S-function discrete state space block. Double precision calculations were performed. Open and closed loop controller realizations were compared with simulink state space (optimal) block. Results of comparison indicate that the optimal non-fragile controller realization shows better results both in open loop and closed loop realization.

Three Semi-empirical Analytic Expressions for the Radial Distribution Function of Hard Spheres

Three simple analytic expressions satisfying the limitation condition at low densities for the radial distribution function of hard spheres are developed in terms of a polynomial expansion of nonlinear base functions and the Carnahan-Starling equation of state. The simplicity and precision for these expressions are superior to the well-known Percus Yevick expression. The coefficients contained in these expressions have been determined by fitting the Monte Carlo data for the first coordination shell, and by fitting both the Monte Carlo data and the numerical results of PercusYevick expression for the second coordination shell. One of the expressions has been applied to develop an analytic equation of state for the square-well fluid, and the numerical results are in good agreement with the computer simulation data.

The Frequency of Y Alu Polymorphism （YAP） Indel in the Minangkabau Malays in Peninsular Malaysia

Background： Minangkabau Malays （Melayu Minangkabau） is one of the Malay sub ethnic groups in Peninsular Malaysia. During the late 17th and early 18th centuries, migration of the Minangs from West Sumatra to the state of Negeri Sembilan Darul Khusus in Peninsular Malaysia took place and their descendants now form the main sub ethnic group in this state. The genetic polymorphisms of Y chromosome at DYS 287 locus were analyzed in Minangkahau Malays. Methods： A total of 41 buccal cells from healthy unrelated individual＇s males from Minangkabau Malays were typed for the DYS 287. The PCR products were separated on 2% （w/v） agarose gel followed by visualization under UV light. Results： Three out of 41 samples （7.32%） showed insertion （YAP＋） polymorphism, while the rest of the samples （92.68%） showed deletion （YAP-） polymorphism. This is the first report concerning the YAP in Malay population at Peninsular Malysia. Conclusion： The vAluable data obtained in this study will contribute to fill in the gap in the knowledge of YAP distribution in Malaysian population and will allow continuous interpretation of the evolution of YAP.

Performance Analysis of Mini Centrifugal Pump with Splitter Blades

Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter blades.Further, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

EXPONENTIAL STABILITY OF A REPARABLE MULTI-STATE DEVICE

The exponential stability of a multi-state device is discussed in this paper. We present that the Co-semigroup generated by the system operator is quasi-compact and irreducible. It is known that 0 is a simple eigenvalue of the system operator. In combination with this, we obtain that the time-dependent solution exponentially converges to the steady-state solution, which is the positive eigenfuction corresponding to the simple eigenvalue O.

THE ASYMPTOTIC BEHAVIOR OF GLOBAL SMOOTH SOLUTIONS TO THE MACROSCOPIC MODELS FOR SEMICONDUCTORS

The authors study the asymptotic behavior of the smooth solutions to the Cauchy problems for two macroscopic models (hydrodynamic and drift-diffusion models) for semiconductors and the related relaxation limit problem. First, it is proved that the solutions to these two systems converge to the unique stationary solution time asymptotically without the smallness assump- tion on doping profile. Then, very sharp estimates on the smooth solutions, independent of the relaxation time, are obtained and used to establish the zero relaxation limit.

Evidence for a Dirac nodal-line semimetal in SrAs_3

Dirac nodal-line semimetals with the linear bands crossing along a line or loop, represent a new topological state of matter. Here, by carrying out magnetotransport measurements and performing first-principle calculations, we demonstrate that such a state has been realized in high-quality single crystals of SrAs_3.We obtain the nontrivial ∏ Berry phase by analysing the Shubnikov-de Haas quantum oscillations. We also observe a robust negative longitudinal magnetoresistance induced by the chiral anomaly.Accompanying first-principles calculations identifies that a single hole pocket enclosing the loop nodes is responsible for these observations.

Influence of temperature and diffusive entropy on the capture radius of fly-casting binding

The recognition and binding of proteins through the "fly-casting" mechanism are important biological processes. In this paper, a physical model for fly-casting binding is described based on the capillarity theory for protein chains. It is found that the capture radius for the fly-casting binding process is maximized at the transition temperature at which the free energy of the monomeric extended state of the protein equals that of the folded state. The factors related to the folding barrier or binding affinity do not change the condition needed to realize the optimization for fly-casting processes. These results will aid in the comprehensive understanding of binding processes.

Clinical Observations on 46 Cases of Globus Hystericus Treated with Modified Banxia Houpu Decoction

Objective： To observe the therapeutic effect and mechanism of modified Banxia Houpu decoction on globus hystericus. Methods： The 95 patients with globus hystericus were randomly divided into a treatment group of 46 cases treated with modified Banxia Houpu decoction and a control group of 49 cases treated with Manyanshuning （Granula for Clearing the Throat）. In addition, a normal group of 24 healthy people was set up. SCL-90 scale was adopted to observe the therapeutic effect, evaluate the psychological state of patients and build a database on combination of four diagnoses. Results： The effect of the modified Banxia Houpo decoction was better than that of the control group in relieving depression, anxiety and improving the psychological state （P〈0.05 or P〈0.01）. Conclusion： Modified Banxia Houpu decoction has definite therapeutic effect on globus hystericus. Its mechanism may be related to its function in relieving depression and anxiety and regulating the osvchological state.

Graphene-GaN Schottky diodes

The electrical characteristics of graphene Schottky contacts formed on undoped GaN semiconductors were investigated. Excellent rectifying behavior with a rectification ratio of -10^7 at ±2 V and a low reverse leakage current of 1.0 × 10^-8 A/cm^2 at -5 V were observed. The Schottky barrier heights, as determined by the thermionic emission model Richardson plots, and barrier inhomogeneity model, were 0.90, 0.72, and 1.24 ± 0.13 eV, respectively. Despite the predicted low barrier height of -0.4 eV at the graphene-GaN interface, the formation of excellent rectifying characteristics with much larger barrier heights is attributed to the presence of a large number of surface states （1.2 x 1013 states/cm2/eV） and the internal spontaneous polarization field of GaN, resulted in a significant upward surface band bending or a bare surface barrier height as high as of 2.9 eV. Using the S parameter of 0.48 （measured from the work function dependence of Schottky barrier height） and the mean barrier height of 1.24 eV, the work function of graphene in the Au/graphene/GaN stack could be approximately estimated to be as low as 3.5 eV. The obtained results indicate that graphene is a promising candidate for use as a Schottky rectifier in GaN semiconductors with n-type conductivity.