First, we reduce the calculation of K2(F2[C4×C4]) to that of the relative K2-group K2(F2C4[t]/(t4),(t)) of the truncated polynomial ring F2C4[t]/(t4). Then we give a minimal generating set of K2(F2[C4×C4]) by subtle calculations of Dennis-Stein symbols. Finally we show that K2(F2[C4×C4])=C34 ⊕ C92.
We have obtained the law of the iterated logarithm for random sums of a double sequence of random variables {ξn,j; n≥1,j≥1}, where {ξn,j; n≥1,j≥1} are independent and for any fixed n, {ξn,j; j≥1} have the same distribution.
The higher order Boolean (control) network is introduced and its topological structure is studied. Using semi-tensor product of matrices, its dynamics is converted into two algebraic forms, which are standard discrete-time dynamic systems. The one-to-one correspondence of the network dynamics and its first algebraic form is proved, and certain topological structures, including fixed points, cycles, and transient time, of higher order Boolean (control) networks are revealed. The relationship between the original system and its second algebraic form is also studied.
CN-loss photodissociation of the C6H5CN+ ion has been studied within the C 2v symmetry using CASSCF and CASPT2 methods. The CASPT2//CASSCF dissociation potential energy curves (PECs) for the five lowest-lying states were calculated. By checking the relative energies, the fragmental geometries, and the charge and spin density populations of the asymptote products along the PECs, we conclude that the 12A1, 12B1, 12A2, 22B1, and 12B2 states of C6H5CN+ correlate with C6H+5 (X1A1) + CN (X2Σ+), C6H+5 (13B1) + CN (X2Σ+), C6H+5 (11A2) + CN (X2Σ+), C6H+5 (11B1) + CN (X2Σ+), and C6H+5 (X1A1) + CN (12Π), which are the first, second, third, fourth, and fifth dissociation limits, respectively.
F--doped lithium vanadium oxides Li1+xV3O8-yFy was synthesized by a solid state reaction at moderate-heating temperature with Li2CO3 and V2O5 as raw materials. Crystal structures were characterized by XRD and electrochemical properties were studied by charge-discharge performance test, cyclic voltammetry test, and conductance test. The XRD results indicate that the products are pure without any impurities. Li1+xV3O8-yFy (y=0.1) shows the best electrochemical cyclability. The first discharge specific capacity is 252.08mAh/g, and the attractive specific capacity of 210.93 mAh/g is obtained after 25 cycles at 0.2c.
Calculations of the Fraunhofer diffraction integrals for the translucent particles of irregular shape are discussed. Three kinds of new 1D contour integral for diffraction are derived by means of scalar Kirchhoff theory, and they are equivalent to each other and can get rid of the drawbacks of regional division in usual 2D surface integrals. Finally, analytical formula of diffraction integrals for the particles with arbitrarily polygonal projection are obtained.
It is important to explicit the competitive levels and features of equipment manufacturing industries in Northeast China in the revitalization of the equipment manufacturing. We integrated shift-share method with the evaluation index of competitiveness, and evaluated the competitive levels, competitive structure, and influence factors of seven northeast equipment manufacturing industries. The results are as follows: 1) there are 4, 2, and 1 fast growth sections in Liaoning, Jilin, and Heilongjiang, respectively; 2) the standard, appliance, and transport equipment sections are at significant growing and competitive advantages; 3) the competitive structure features are market-technology, efficiency-structure, and structure-innovation; 4) the new influence factors such as senior human resource, technological innovation, and FDI are not significant.
Q-value structure of the crust is of great significance for understanding of non-elastic nature of crustal structure, thermal activity, crustal inhomogeneity, and fault distribution. We present an interactive software for three-dimensional Q tomography based on absorption characteristic time t*. Amplitude spectra of seismic data (P-wave and S-wave) can then be calculated quickly and easily, absorption characteristic times can be obtained through fitting amplitude spectra, and three-dimensional Q structure can be obtained by using the Q tomography method and t* data. The real example shows that the method and software are effective and feasible.
Caliban is a tumor suppressor. To understand its inherent mechanisms, we screened Caliban interacting proteins using the yeast two-hybrid system. We found four new Caliban interacting proteins, Bip2, Uba2, RpS27A, and CG7182. Moreover, over-expression of transcriptional factor Bip2 suppresses transcription of p 53. The tumor suppression function of p53 could be regulated through new mechanisms involving Bip2 and Caliban.
We analyse the systematic model and working principle of distributed satellites SAR system based on three-dimensional reconstruction principle of InSAR system and present a complete closed-form solution to the three-dimensional geo-location of targets. Meanwhile we analyse the main error sources, baseline error and interferometric phase error, which influence the precision of digital elevation models (DEM) acquisition. Finally, simulations are made for analyses of the characteristics of baseline error and interferometric phase error, which provides a basis for calibration and correction of systematic parameters.
On the basis of our study on SAR imaging algorithm in 2D frequency domain, we propose a modified range migration algorithm (RMA) using range sub-blocks in range-Doppler domain (RDB-RMA), and make a comparison between our proposed algorithm and other two algorithms, approximate RMA and scaled inverse Fourier transformation algorithm (SIFTA). The simulation data show that RDB-RMA is better in focusing capabilitity than the other two algorithms, when the swath is very wide and the range migration is very large. By comparing these algorithms, we conclude that RDB-RMA is better in computing efficiency than SIFTA. Finally, an experiment carried out on measured data confirms feasibility of the proposed algorithm.
Considering the mass data and complex criterions of payload telemetry, we propose a technology of automatic discrimination for payload telemetry data based on C language integrated production system (CLIPS). This technology realizes not only the descriptions of complex discrimination rules by adopting the expert system language CLIPS but also the dynamic discrimination of telemetry data varying with the state of payloads by introducing finite state machine. Besides, we design the auxiliary learning algorithm of discrimination knowledge by mining rules from frequent patterns and improve the speed of discrimination by using reasoning mechanism of CLIPS. Thus this technology can meet the requirement of data discrimination for payload system test and flight control, and dramatically improves the efficiency and veracity of discrimination.It has been successfully applied to some satellite projects.
Considering trajectory tracking of free-floating space robot with uncertainties and friction blind section non-linearity, we propose an adaptive fuzzy CMAC compensation control algorithm. The control scheme uses fuzzy neural network to establish modeling online, and imports GL matrix and multiplication operator "." into neural network to distinguish parameters of system and friction blind section non-linearity. The control scheme can guarantee the stability of closed loop system and the asymptotic convergence of tracking errors. Neural network approach errors and outside disturbance can be eliminated by sliding model controller. Based on a standard Lyapunov theorem, we prove that all signals in the closed-loop are bounded. The simulation results show that the controller can achieve high control precision and meet the requirement of real time.
A cooperation diversity-aware routing metric for 802.11s-based wireless Mesh networks(WMNs) is proposed. Furthermore, a cooperation diversity-aware routing protocol (CDARP) and a cooperative MAC protocol (CMAC) are proposed, and both the protocals are adapted to the characteristic of WMNs. By building up virtual nodes and calculating the routing metric for virtual links, CDARP-CMAC can select the most reasonable path to cooperatively transmit packets. The simulation results show that, compared to the traditional cooperation scheme, CDARP-CMAC improves the good put by 5%~13% and reduces the drop rate by 5%~10%.
The low-level video feature extractions are the most time-consuming components in content-based video information retrieval systems. In this paper we study parallelization and performance optimization methods of four video feature extractions on multi-core systems. Experiments show that the processing speeds of these programs are 17 times the original processing speed on average when eight cores are used. Besides, detailed performance analysis helps us find bottlenecks and suggest ways to further improve multi-core systems performance in future.
The existence of odd perfect numbers is a well-known open problem in number theory. We prove that if n is an odd perfect number which is relatively prime to 3, then ω(n)≥16, where ω(n) is the number of distinct prime factors of n.
Brassica juncea L. is a Zn/Cd tolerance plant, and the gene expression of heavy metal ATPase (HMA) has not been reported. In the present work, two cDNA fragments of BjHMA, BjHMA 3 and BjHMA 4 , were isolated from B. juncea seedling. Real-time quantitative PCR analysis revealed that both BjHMA 3 and BjHMA 4 were constitutively expressed in all tissue and preferentially in root. The mRNA profile of BjHMA 3 or BjHMA 4 was the lowest in leaf while the expressions were strongly enhanced by Zn or Cd stress, indicating that BjHMA played important roles in growth and in heavy metal homeostasis and tolerance in plant.
An improved threat model of potential field theory is used to plan practical 3D track. Terrain, radar, and fire threats are classified and analyzed, and formulas are deduced. Search field is limited within a rectangle zone including the start point and destination, which reduces complexity of calculation and ensures convergence to destination. The flight line is confined by using the gradient restriction smoothing algorithm and curvature limit smoothing algorithm, which is suitable for aircraft mobility.