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1.
In this paper, we obtain the factorization of direct production and order of group GL(n, Z m ) in a simple method. Then we generalize some properties of GL(2, Z p ) proposed by Huppert, and prove that the group \(GL\left( {2,{Z_{{z^\lambda }}}} \right)\) is solvable. We also prove that group GL(n, Z p ) is solvable if and only if GL(n, Z p ) is solvable, and list the generators of groups GL(n, Z p ) and SL(n, Z p ). At last, we prove that PSL(2, Z p )(p > 3) and PSL(n, Z p )(n > 3) are simple.  相似文献   

2.
The type II toxin-antitoxin genes are responsible for the phenotypic switch to a quasi-dormant state that enables cell survival under stresses, a similar function to heterocyst of cyanobacteria. In this paper, we particularly study the role of gene pair all3211-asl3212 under Spectinomycin stress to reveal how the type II toxin-antitoxin involved in environmental stress responses. Bioinformatics prediction shows that toxin protein gene All3211 is homologous to MazF, a member of mazEF family that encoding nucleases. We clone gene all3211-asl3212 into expression vectors to identify its molecular characteristics. Deletion mutant strains of all3211-asl3212 are selected in a tri-parental mating screen. Phenotype comparisons of mutant and wild type reveals no difference of single-deletion-mutants in pigment integrity, the sensitivity to antibiotics, and heterocyst formation. The results show that deletion mutation of single TAS gene pair all3211-asl3212 results in limited effects on the cellular growth of PCC 7120. Thus, we suggest that dosage compensating might be provided from redundant genes or bypass pathways to offset obvious phenotypic differences.  相似文献   

3.
In this paper, a new Lp-dual mixed geominimal surface area is defined by Lp-dual mixed quermassintegrals, which extends the definition of Lp-dual geominimal surface area and generalizes some related inequalities established by Wan and Wang.  相似文献   

4.
Recently, the connection between p-measures of asymmetry and the Lp -mixed volumes for convex bodies was found soon after the p-measure of asymmetry was proposed, and the Orlicz-measures of asymmetry was proposed inspired by such a kind of connection. In this paper, by a similar way the dual p -measures of asymmetry for star bodies (naturally for convex bodies) is introduced first. Then the connection between dual p -measures of asymmetry and Lp -dual mixed volumes is established. Finally, the best lower and upper bounds of dual p-measures and the corresponding extremal bodies are discussed.  相似文献   

5.
To resist the fast algebraic attack and fast selective discrete Fourier transform attacks, spectral immunity of a sequence or a Boolean function was proposed. At the same time, an algorithm to compute the spectral immunity of the binary sequence with odd period N was presented, here N is a factor of 2 n ? 1, where n is an integer. The case is more complicated when the period is even. In this paper, we compute linear complexity of every orthogonal sequence of a given sequence using Chan-Games algorithm and k - error linear complexity algorithm. Then, an algorithm for spectral immunity of binary sequence with period N = 2 n is obtained. Furthermore, the time complexity of this algorithm is proved to be O(n).  相似文献   

6.
The influence of Nd addition on the glass-forming ability (GFA), microhardness, and corrosion resistance of Mg60-xCu40Ndx (x=5, 10, 15, 20, and 25, at%) alloys were investigated by differential scanning calorimetry, Vickers-type hardness tests, and electrochemical methods. The results suggest that the GFA and microhardness of the amorphous alloys increase until the Nd content reaches 20at%. The corrosion potential and corrosion current density obtained from the Tafel curves indicate that the Mg35Cu40Nd25 ternary alloy exhibits the best corrosion resistance among the investigated alloys. Notably, nanoporous copper (NPC) was synthesized through a single-step dealloying of Mg60-xCu40Ndx (x=5, 10, 15, 20, and 25) ternary alloys in 0.04 mol·L-1 H2SO4 solution under free corrosion conditions. The influence of dealloying process parameters, such as dealloying time and temperature, on the microstructure of the ribbons was also studied using the surface diffusivity theory. The formation mechanism of dealloyed samples with a multilayered structure was also discussed.  相似文献   

7.
149 complete mitochondrial DNA (mtDNA) cytochrome b (Cyt b) genes (1140 bp) of Gymnocypris przewalskii, Gymnocypris eckloni and Gymnocypris scolistomus from the Lake Qinghai, Yellow River and Qaidam Basin were sequenced and analyzed. Consistent dendrogram indicated that the samples collected from the same species do not constitute a separate monophyletic group and all the samples were grouped into three highly divergent lineages (A, B and C). Among them, Lineage A contained all samples of G. przewalskii from the Lake Qinghai and partial samples of the G. eckloni from the Yellow River. Lineage B contained the remaining samples of G. eckloni from the Yellow River. Lineage C was composed of a monophyletic group by G. eckloni from the Qaidam Basin. Analysis of molecular variance (AMOVA) indicated that most of genetic variations were detected within these three mtDNA lineages (93.12%), suggesting that there are three different lineages of Gymnocypris in this region. Our Cyt b sequence data showed that G. przewalskii was not a polytypic species, and G. scolistomus was neither an independent species nor a subspecies of G. eckloni. The divergent mtDNA lineages of G. eckloni from the Yellow River suggested that gene flow between the different populations was restricted to a certain extent by several gorges on the upper reach of the Yellow River. Lineage B of G. eckloni might be the genetic effect from the ancestor which was incorporated with the endemic schizothoracine fishes when the headward erosion of the Yellow River reached to its current headwaters of late. The G. eckloni from Basin Qaidam was a monophyletic group (lineage C) and Fst values within G. eckloni from the Yellow River were higher than 0.98, suggesting that the gene flow has been interrupted for a long time and the G. eckloni from Basin Qaidam might have been evolved into different species by ecology segregation. The correlation between the rakers number of Gymnocypris and population genetic variation was not significant. All Gymnocypris populations exhibited a low nucleotide diversity (π = 0.00096–0.00485). Therefore the Gymnocypris populations from Basin Qaidam could have experienced severe bottleneck effect in history. Our result suggested Gymnocypris populations of Basin Qaidam should give a high priority in conservation programs.  相似文献   

8.
The electron states confined in wurtzite InxGa1-xN/GaN strained quantum dots (QDs) have been investigated in the effective -mass approximation by solving the Schrtdinger equation, in which parabolic confined potential and strong built-in electric field effect (due to the piezoelectricity and spontaneous polarization) have been taken into account. The real part Rex^(3)(0,0,ω) and the imaginary part Imx^(3)(0,0,ω) of the third-order susceptibil- ity describe quadratic electro-optic effects and electro-absorption process of the QDs respectively. And both of them have been calculated in directions parallel and vertical to z axis. Furthermore, the study shows Rex^(3)(0,0,ω) and Imx^(3)(0,0,ω) increase under resonant conditions with the QDs' radius and height increase, and the same results occur when the content increase. In addition, the resonant position shift to the lower energy region when the parabolic frequencies increase.  相似文献   

9.
Virus isolate Y47 was obtained fromMalvastrum coromandelianum showing yellow vein symptom in Honghe, Yunnan Province. The complete nucleotide sequence of DNA-A was determined, it contains 2731 nucleotides, having typical genomic organization of a begomovirus, encoding 6 ORFs with 2 ORFs [AV1(CP) and AV2] in virionsense DNA and 4 ORFs (AC1–AC4) in complementarysense DNA. Comparisons show that the total DNA-A of Y47 has the highest sequence identity (77%) with that ofOkra yellow vein mosaic virus- [201] (AJ002451), while less than 76% identities are found when compared with other begomoviruses. The molecular data show that virus isolate Y47 is a distinct begomovirus species, for which the nameMalvastrum yellow vein virus is proposed. Satellite DNA molecule (Y47β) was found to be associated with Y47 using the primers (beta01 and beta02) specific for DNAβ. Y47β consists of 1348 nucleotides, with a functional ORF (C1) in complementary-sense DNA. Y47β has 62%–67% sequence identity with DNAβ molecule associated withCotton leaf curl Multan virus orCotton leaf curl Rajasthan virus, while lower than 46% sequence identities are found when compared with other reported DNAβ molecules. Relationship dendrograms show that DNAβ molecules are co-evolved with their help begomoviruses.  相似文献   

10.
Based on Lutwak’s the notion of Lp-difference bodies, Wang and Ma introduced asymmetric Lp-difference bodies and gave their extremum values for volumes. In this paper, we establish the extremum value inequalities for the quermassintegrals and dual quermassintegrals of asymmetric Lp-difference bodies and their polars, respectively.  相似文献   

11.
In microbial fuel cell (MFC), the rate of electron transfer to anode electrode is a key intrinsic limiting factor on the power output of MFCs. Using Klebsiella pneumoniae (K. pneumoniae) strain L17 as biocatalyst, we studied the mechanism of electron shuttle via self-producing mediator in a cubic air-chamber MFC. To eliminate the influence of biofilm mechanism, the anode electrode was coated with microfiltration membrane (0.22 μm). Data showed that the microfiltration membrane coated and uncoated MFCs achie...  相似文献   

12.
The enzyme OtsA (trehalose-P synthase) plays a critical role in the biosynthesis of trehalose, which is a nonreducing disaccharide that plays important functions in many organisms. By using light scattering technique, we discovered that OtsA in Arthrobacter strain A3 polymerized in the presence of divalent metal ions (Mg2+ or Ca2+), and the kinetics of the assembly was dependent on their concentrations. We identified potential compounds that can affect the kinetics of the polymerization, particularly, heparin, which acts as a very promising inhibitor of the polymerization. The OtsA assembly turns out to be a very delicate process that is finely regulated by pH. OtsA may be in the polymerized form at physiological pH in vivo, suggesting a more complicated mechanism of the enzyme. These unique properties of OtsA provide novel insights into the molecular mechanism of the biosynthesis of trehalose.  相似文献   

13.
In order to investigate the chemical-biological relationship caused by the special processing technology,the constituent's content and antioxidant capacity in vivo of Euphorbia fischeriana Steud processing Terminalia chebula Retz. have been tested. Taking T. chebula Retz. as control,the content of gallic acid is analyzed with high performance liquid chromatography(HPLC) method. The results show that the increase of gallic acid concentration from 4.54% to 7.46% leads to enhancement of the antioxidant capacities in vivo of the E. fischeriana Steud processing T. chebula Retz. The significant antioxidant capacity in vivo(p0.05) of the processed product possesses is better than the unprocessed herb. Its superoxide dismutase(SOD)and malondia-ldehyde(MDA) contents in serum,the MDA content in liver can match the effects of vitamine E when administered at high dosage.  相似文献   

14.
Based on a newly revised inverse scattering transform for the derivative nonlinear Schrödinger (DNLS+) equation with nonvanishing boundary condition (NVBC), the explicit breather-type and pure N-soliton solution has been derived by some algebra techniques. The two-breather solution and the pure double-soliton solution have been given as two typical examples in illustration of the general formula of the multi-soliton solution. The asymptotic behaviors of the N-soliton solution are discussed in detail.  相似文献   

15.
This paper considers linearized BCL system with viscosity which is firstly derived by J. L. Bona, T. Colin and D. Lannes for the study of motion of water waves. L 2 decay estimate is got by means of Fourier analysis and frequency decomposition. This result plays key role in studying the global well-posedness of corresponding nonlinear system.  相似文献   

16.
LiNbO3 waveguiding films with highly C-axis orieatation and superior crystallographic quality have been deposited on the amorphous SiO2 buffer layer of Si wafer by pulsed laser deposition (PLD) technique. X-ray diffraction,high-resolution electron transmission microscopy and atomic force microscopy were applied to characterizing the quality and orientaion of LiNbO3 thin film, and the optimized depositioa coaditioas have been determined for C-axis oriented growth. LiNbO3 thin films on amorphous SiO2 buffer layer were composed of intimate arrangements of quadrangular single crystal domain (150 nm x 150 nm) with C-axis orientatioa, and displayed sharp interface structures. The measurements of prism coupling technique indicate that the laser can be coupled into the LiNbO3 film and TE and TM waveguiding modes were detected. In addition, the possible mechanism of oriented growth on amorphous buffer layer and “film-substrate effects“ were discussed briefly, which suggests that its growth mechanism is likely analogous to the Voimer model with characteristics of three-dimensional islands nucleation on the smooth crystal surface.  相似文献   

17.
The effect of Si on the austenite stabilization, martensite morphology, and magnetic properties in Fe-26%Ni-x%Si (x=3.5, 5, and 6) alloys have been studied by means of transmission electron microscopy (TEM) and Mössbauer spectroscopy techniques. TEM observations reveal that the martensite morphology is closely dependent on the Si content. The volume fraction changes of martensite and austenite phases, the hyperfine magnetic field, and isomer shift values have been determined by Mössbauer spectroscopy. The Mössbauer study reveals that the hyperfine magnetic field, the isomer shift values and the volume fraction of martensite decrease with increasing Si content.  相似文献   

18.
In this paper, the generalized inverse eigenvalue problem for the (P,Q)-conjugate matrices and the associated approximation problem are discussed by using generalized singular value decomposition (GSVD). Moreover, the least residual problem of the above generalized inverse eigenvalue problem is studied by using the canonical correlation decomposition (CCD). The solutions to these problems are derived. Some numerical examples are given to illustrate the main results.  相似文献   

19.
An in situ characterization technique called electrochemical noise (ECN) was used to investigate the bioleaching of natural pyrite. ECN experiments were conducted in four active systems (sulfuric acid, ferric-ion, 9k culture medium, and bioleaching solutions). The ECN data were analyzed in both the time and frequency domains. Spectral noise impedance spectra obtained from power spectral density (PSD) plots for different systems were compared. A reaction mechanism was also proposed on the basis of the experimental data analysis. The bioleaching system exhibits the lowest noise resistance of 0.101 MΩ. The bioleaching of natural pyrite is considered to be a bio-battery reaction, which distinguishes it from chemical oxidation reactions in ferric-ion and culture-medium (9k) solutions. The corrosion of pyrite becomes more severe over time after the long-term testing of bioleaching.  相似文献   

20.
This paper investigates the selective liquid response for Morpho didius butterfly wing scales and propose an optical model to explain the effect of different components on the liquid response. It is found out that the reason of the selective response is that the liquid media forms nanometre-thick films between ridge-lamellae nanostructures and changes the constructive interference wavelength. There is linear relation between the structural color of ridge-lamellae structure and index of liquid background media. The reason of vapor’s responses is that the nanometre-thick liquid films on ridge-lamellae nanostructures change the constructive interference wavelength. These liquid films are formed due to vapor adsorption. Therefore, the selective linear liquid response can be applied to design nano-engineered photonic liquid and vapor sensors.  相似文献   

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