Abstract:
With the sparistiy of the target space, a novel migration imaging algorithm for the stepped-frequency GPR based on compressive sensing is proposed in this paper. The new imaging algorithm removes the direct wave in frequency domain in advance, estimates the regulation parameter with cross validation algorithm, and images the subsurface with sparistiy constraint. The simulation and experimental data show that the new imaging algorithm is effective and practical.

Abstract:
Powerful and accurate computation is becoming one of the most important tools for rock failure process analysis and related rock engineering problems.It demands supercomputer or large-scale parallel computer and related software that can be run on them.Common personal computers(PC) and workstations are incapable when they are facing the accurate simulation of micro-scale crack formation and evolution in rocks and other different typs of materials,which requires terascale computing,even petascale super-computing in future.A parallel model of rock failure process analysis is proposed.This model is developed from serial version of rock failure process analysis(RFPA) directly,which has been presented before.Parallelism of finite element method(FEM) in stress module has been completed using discontinuous finite element method and domain decomposition parallel algorithms for parallelization of RFPA.Numerical test shows that the program is robust and possesses good scalability and pocketability.Stress analysis of tens of millions order linear equations has been finished within twenty five minutes on 32-node PC-cluster.

Abstract:
Streptomyces xinghaiensis is a novel Streptomyces species isolated from marine sediment sample collected in Xinghai Bay, Dalian, China, and wide spectrum of antimicrobial activities of its fermentation broth has been observed. In this study, the antibacterial activities of the fermentation broth of S. xinghaiensis against drug-resistant clinical isolates were investigated, and inhibitory activities against Acinetobacter baumannii and Staphylococcus aureus (MRSA) strains were revealed. Purification of the active compound (s) against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates was performed and the properties of the active compounds were studied. Active fractions were obtained after treatments of the broth with macroporous adsorptive resin HP-20 and Sephadex LH-20. The active components were weak alkaloid compounds with no specific UV adsorption, and ninhydrin coloration further supported the hypothesis that the active compounds likely belong to aminoglycoside antibiotics. The draft genomic sequence of S. xinghaiensis was searched and a ribostamycin-related gene cluster was identified. However, Thin Layer Chromatography (TLC) analysis indicated that the major components of the active compounds are different from ribostamycin.

Abstract:
In order to realize a stone detection based on machine vision, SUSAN operator was used to segment an original image. The areas where stones may exist could be obtained by using edge track filter in the segmented image. The area in the original image could be dwindled by using a segmentation method based on invariable moments. A grads image could be obtained by using Sobel operator to enhance the edge of this area. The grads image was segmented and filtered by using edge track. The stone position in the original image could be acquired by coordinating projection for the grads image. Experiment results show that the proposed method is characterized by a definite adaptability to environment and real-timeness.

Abstract:
Radiative E1 decay widths of $\rm X(3872)$ are calculated through the relativistic Salpeter method, with the assumption that $\rm X(3872)$ is the $\chi_{c1}$(2P) state, which is the radial excited state of $\chi_{c1}$(1P). We firstly calculated the E1 decay width of $\chi_{c1}$(1P), the result is in agreement with experimental data excellently, then we calculated the case of $\rm X(3872)$ with the assignment that it is $\chi_{c1}$(2P). Results are: ${\Gamma}({\rm X(3872)}\rightarrow \gamma \sl J/\psi)=33.0$ keV, ${\Gamma}({\rm X(3872)}\rightarrow \gamma \psi(2S))=146$ keV and ${\Gamma}({\rm X(3872)}\rightarrow \gamma \psi(3770))=7.09$ keV. The ratio ${{\rm Br(X(3872)}\rightarrow\gamma\psi(2{\rm S}))}/{{\rm Br(X(3872)}\rightarrow \gamma {\sl J}/\psi)}=4.4$ agrees with experimental data by BaBar, but larger than the new up-bound reported by Belle recently. With the same method, we also predict the decay widths: ${\Gamma}(\chi_{b1}(1\rm P))\rightarrow \gamma \Upsilon(1\rm S))=30.0$ keV, ${\Gamma}(\chi_{b1}(2\rm P))\rightarrow \gamma \Upsilon(1\rm S))=5.65$ keV and ${\Gamma}(\chi_{b1}(2\rm P))\rightarrow \gamma \Upsilon(2S))=15.8$ keV, and the full widths: ${\Gamma}(\chi_{b1}(1\rm P))\sim 85.7$ keV, ${\Gamma}(\chi_{b1}(2\rm P))\sim 66.5$ keV.

Abstract:
For a supersonic Euler flow past a straight wedge whose vertex angle is less than the extreme angle, there exists a shock-front emanating from the wedge vertex, and the shock-front is usually strong especially when the vertex angle of the wedge is large. In this paper, we establish the $L^1$ well-posedness for two-dimensional steady supersonic Euler flows past a Lipschitz wedge whose boundary slope function has small total variation, when the total variation of the incoming flow is sufficiently small. In this case, the Lipschitz wedge perturbs the flow and the waves reflect after interacting with the strong shock-front or the wedge boundary. We first obtain the existence of solutions in $BV$ when the incoming flow has small total variation by the wave front tracking method and then study the $L^1$ stability of the solutions. In particular, we incorporate the nonlinear waves generated from the wedge boundary to develop a Lyapunov functional between two solutions, which is equivalent to the $L^1$ norm, and prove that the functional decreases in the flow direction. Then the $L^1$ stability is established, so is the uniqueness of the solutions by the wave front tracking method. Finally, we show the uniqueness of solutions in a broader class, i.e. the class of viscosity solutions.

Abstract:
Communication channels are said to be underspread if their coherence time is greater than their delay spread. In such cases it can be shown that in the infinite bandwidth limit the information capacity tends to that of a channel with perfect receiver Channel State Information (CSI). This paper presents a lower bound on the capacity of a channel with finite bandwidth, expressed in a form which is mathematically elegant, and computationally simple. The bounding method exploits the fact that most actual channels are highly underspread; and that typically more is known about their impulse response than the channel time variation. The capacity is lower bounded by finding an achievable rate for individual time blocks which are shorter than the channel coherence time, in an orthogonal frequency division multiplexing system model. A highly underspread channel of particular interest is the invehicle channel, and a numerical example is given to verify that the capacity is indeed approximately that of a channel with perfect receiver CSI. The resulting lower bound is shown to be tighter than those previously derived.

Abstract:
The stability of boundary pillar,which can be found across in mine shifting from open-pit to underground mining,is very important for safe production of underground mine. Based on the practice of Shirengou ore mine from open-pit to underground mining,the stabilities of boundary pillar at representative sections are calculated and analyzed by using the methods of limit equilibrium and numerical simulation. With the application of the limit equilibrium method and consideration of the thickness,span of boundary pillar,height of deposed rock,and obliquity of ore mine,the safety coefficients of all sections of boundary pillar are calculated, respectively. The safe thickness for boundary pillar has been modeled by the RFPA2D (rock failure process analysis)system,including deformation and failure of boundary pillar during caving. At the same time,the failure process of the different sections is simulated. By calculation,the safety and danger section of the boundary pillar is predicted. It validates the designed boundary pillar thickness and offers references to construction.