Two-Dimensional Riemann Problems:Transonic Shock Waves and Free Boundary Problems

We are concerned with global solutions of multidimensional(M-D)Riemann problems for nonlinear hyperbolic systems of conservation laws,focusing on their global configurations and structures.We present some recent developments in the rigorous analysis of two-dimensional(2-D)Riemann problems involving transonic shock waves through several prototypes of hyperbolic systems of conservation laws and discuss some further M-D Riemann problems and related problems for nonlinear partial differential equations.In particular,we present four different 2-D Riemann problems through these prototypes of hyperbolic systems and show how these Riemann problems can be reformulated/solved as free boundary problems with transonic shock waves as free boundaries for the corresponding nonlinear conservation laws of mixed elliptic-hyperbolic type and related nonlinear partial differential equations.

Estimation of Two-Dimensional Correction Factors for Min-Sum Decoding of Regular LDPC Code

In this paper, two-dimensional (2-D) correction scheme is proposed to improve the performance of conventional Min-Sum (MS) decoding of regular low density parity check codes. The adopted algorithm to obtain the correction factors is simply based on estimating the mean square difference (MSD) between the transmitted codeword and the posteriori information of both bit and check node that produced at the MS decoder. Semi-practical tests using software-defined radio (SDR) and specific code simulations show that the proposed quasi-optimal algorithm provides a comparable error performance as Sum-Product (SP) decoding while requiring less complexity.

Proteome analysis of round-headed and normal spermatozoa by 2-D fluorescence difference gel electrophoresis and mass spectrometry

Globozoospermia is a severe form of teratozoospermia characterized by round-headed spermatozoa with an absent acrosome, an aberrant nuclear membrane and midpiece defects. Globozoospermia is diagnosed by the presence of 100% round-headed spermatozoa on semen analysis, and patients with this condition are absolutely infertile. The objective of this study was to investigate the differences in protein expression between human round- headed and normal spermatozoa. Two-dimensional （2-D） fluorescence difference gel electrophoresis （DIGE） coupled with mass spectrometry （MS） was used in this study. Over 61 protein spots were analysed in each paired normal/round-headed comparison, using DIGE technology along with an internal standard. In total, 35 protein spots identified by tandem mass spectrometry （MS/MS） exhibited significant changes （paired t-test, P 〈 0.05） in the expression level between normal and round-headed spermatozoa. A total of nine proteins were found to be upregulated and 26 proteins were found to be downregulated in round-headed spermatozoa compared with normal spermatozoa. The differentially expressed proteins that we identified may have important roles in a variety of cellular processes and structures, including spermatogenesis, cell skeleton, metabolism and spermatozoa motility.

APPLICATION OF TWO-DIMENSIONAL WAVELET TRANSFORM IN NEAR-SHORE X-BAND RADAR IMAGES

Among existing remote sensing applications, land-based X-band radar is an effective technique to monitor the wave fields, and spatial wave information could be obtained from the radar images. Two-dimensional Fourier Transform （2-D FT） is the common algorithm to derive the spectra of radar images. However, the wave field in the nearshore area is highly non-homogeneous due to wave refraction, shoaling, and other coastal mechanisms. When applied in nearshore radar images, 2-D FT would lead to ambiguity of wave characteristics in wave number domain. In this article, we introduce two-dimensional Wavelet Transform （2-D WT） to capture the non-homogeneity of wave fields from nearshore radar images. The results show that wave number spectra by 2-D WT at six parallel space locations in the given image clearly present the shoaling of nearshore waves. Wave number of the peak wave energy is increasing along the inshore direction, and dominant direction of the spectra changes from South South West （SSW） to West South West （WSW）. To verify the results of 2-D WT, wave shoaling in radar images is calculated based on dispersion relation. The theoretical calculation results agree with the results of 2-D WT on the whole. The encouraging performance of 2-D WT indicates its strong capability of revealing the non-homogeneity of wave fields in nearshore X-band radar images.

基于投影算法的二维自适应滤波器

提出了一个可以使滤波器的系数同时在水平和垂直方向上更新的二维投影算法,推导了该算法的一些基本性质.为与其他二维自适应算法比较,将该算法应用到二维系统辨识中.仿真结果表明,提出的二维投影算法(MPA)具有好的效果.

2-D/2-D heterostructured biomimetic enzyme by interfacial assembling Mn_(3)(PO_(4))_(2) and MXene as a flexible platform for realtime sensitive sensing cell superoxide

It is critical for fabricating flexible biosensors with both high sensitivity and good selectivity to realize real-time monitoring superoxide anion(O_(2)^(·−)),a specific reactive oxygen species that plays critical roles in various biological processes.This work delicately designs a Mn_(3)(PO_(4))_(2)/MXene heterostructured biomimetic enzyme by assembling two-dimensional(2-D)Mn_(3)(PO_(4))_(2) nanosheets with biomimetic activity and 2-D MXene nanosheets with high conductivity and abundant functional groups.The 2-D nature of the two components with strong interfacial interaction synergistically enables the heterostructure an excellent flexibility with retained 100%of the response when to reach a bending angle up to 180°,and 96%of the response after 100 bending/relaxing cycles.It is found that the surface charge state of the heterostructure promotes the adsorption of O_(2)^(·−),while the high-energy active site improves electrochemical oxidation of O_(2)^(·−).The Mn_(3)(PO_(4))_(2)/MXene as a sensing platform towards O2•−achieves a high sensitivity of 64.93µA·µM^(−1)·cm^(−2),a wide detection range of 5.75 nM to 25.93µM,and a low detection limit of 1.63 nM.Finally,the flexible heterostructured sensing platform realizes real-time monitoring of O_(2)^(·−)in live cell assays,offering a promising flexible biosensor towards exploring various biological processes.

DEVELOPMENT OF THE 2-D COUPLED STRATOSPHERIC-TROPOSPHERIC DYNAMICAL-RADIATIVE-CHEMICAL MODEL—PART Ⅰ:THE DESCRIPTION OF THE MODEL AND ITS PRELIMINARY RESULTS

In this paper,a two-dimensional(2-D)coupled stratospheric-tropospheric dynamical-radiative- chemical model has been developed,and some preliminary results have been given.From these results we can see that the latitude-height distribution characteristics and the seasonal variation of the dynamical fields such as atmospheric temperature,wind field,etc.can be effectively simulated by using this model;and the modelled latitude-height distribution of trace gases gives their distribution characteristics and seasonal variation rather well.All of these are testimony to the strong ability of the model.

Effect of high salinity on cell growth and protein production of Antarctic ice microalgae Chlamydomonas sp. ICE-L

Antarctic ice microalgae Chlamydomonas sp.ICE-L can survive and thrive in Antarctic sea ice.In this study,Chlamydomonas sp.ICE-L could survive at the salinity of 132‰ NaCl.SDS-PAGE showed that the density of 2 bands（26 and 36 kD） decreased obviously at the salinity of 99‰ NaCl compared to at the salinity of 33‰ NaCl.The soluble proteins in Chlamydomonas sp.ICE-L grown under salinity of 33‰ and 99% NaCl were compared by 2-D gel electrophoresis.After shocking with high salinity,8 protein spots were found to disappear,and the density of 28 protein spots decreased.In addition,19 protein spots were enhanced or induced,including one new peptide（51 kD）.The changes of proteins might be correlated with the resistance for Chlamydomonas sp.ICE-L to high salinity.

Research on Application of RFID Technology in the Agricultural Product Quality and Safety Traceability System

Through the study of individual identification technology, the paper put forward the identification scheme for two-dimensional code ear tag ＋ RFID electronic tag, namely using Ministry of agriculture regulations two-dimensional code ear tag to identify individual animal in the breeding stage, and record the basic information and breeding, using the RFID electronic identification tag to record slaughter quarantine information; phase, and finally the ear tag code, RFID electronic tag and product number should be encode relatively to generate tracing code in the final agricultural products, realize the smooth flow of the information flow from the breeding stage to the final product. For fruits and vegetables, agricultural products are adopted the common identification for orchard （greenhouse） numbers units.

NUMERICAL SIMULATION OF WIND-INDUCED MOTION IN SUSPENDED SEDIMENT TRANSPORT

In regions with broad water surfaces such as lakes, reservoirs and coastal areas, the wind stress on the flow motion generates a significant impact. The wind stress is an unsteady force which makes numerical simulation difficult. This paper presents a two-dimensional （2-D） mathematical model of the impact of wind-induced motion on suspended sediment transport at Beijing＇s 13-Ling Reservoir. The model uses the Diagonal Cartesian Method （DCM） with a wetting-drying dynamic boundary to trace variations in the water level. The calculation results have been tested against in situ measurements. The measurements confirm the model＇s accuracy and agreement with the actual situation at the reservoir. The calculations also indicate that wind stress holds the key to suspended sediment transport at Beijing＇s 13-Ling Reservoir, especially when westerly winds prevail.

A framework to express variant and invariant functional spaces for binary logic

A new framework has been developed to express variant and invariant properties of functions operating on a binary vector space.This framework allows for manipulation of dynamic logic using basic operations and permutations.Novel representations of binary functional spaces are presented.Current ideas of binary functional spaces are extended and additional conditions are added to describe new function representation schemes:F code and C code.Sizes of the proposed functional space representation schemes were determined.It was found that the complete representation for any set of functions operating on a binary sequence of numbers is larger than previously thought.The complete representation can only be described using a structure having a space of size 2^(2n)×2^(n)!for any given space of functions acting on a binary sequence of length n.The framework,along with the proposed coding schemes provides a foundational theory of variant and invariant logic in software and electricelectronic technology and engineering,and has uses in the analysis of the stability of rule-based,dynamic binary systems such as cellular automata.