substitution

摘要： Language is the best means of communication with the people in your surroundings.People create or find word to name and describe new things which they never saw,examining the role of the speaker’s native language in loanword adaptation.This study aimed to investigate how the English loanwords into Taif Arabic(TA)are phonologically adapted.The study adopted a qualitative and descriptive approach.The study collected 190 English loanwords from national TA speakers of various ages,genders,and educational levels.These loanwords were transcribed using IPA symbols.Online Cambridge Dictionary is used to compare the pronunciation of the loanwords in DL and RL.The outcomes of this paper discovered that substitution was the most common adaptive process and deletion was the rarest.It can be concluded that the determinant of the adaptation process is the phonological rules of the speaker’s native language.The results of this study are of great benefit to learners of Arabic English.

摘要： While designing and developing encryption algorithms for text and images,the main focus has remained on security.This has led to insufficient attention on the improvement of encryption efficiency,enhancement of hyperchaotic sequence randomness,and dynamic DNA-based S-box.In this regard,a new symmetric block cipher scheme has been proposed.It uses dynamic DNA-based S-box connected with MD5 and a hyperchaotic system to produce confusion and diffusion for encrypting color images.Our proposed scheme supports various size color images.It generates three DNA based Sboxes for substitution namely DNA_1_s-box,DNA_2_s-box and DNA_3_sbox,each of size 16×16.Next,the 4D hyperchaotic system followed by MD5 is employed in a novel way to enhance security.The three DNAbased S-boxes are generated from real DNA sequences taken from National Center for Biotechnology Information(NCBI)databases and are dependent on the mean intensity value of an input image,thus effectively introducing content-based confusion.Finally,Conservative Site-Specific Recombination(CSSR)is applied on the output DNA received from DNA based S-boxes.The experimental results indicate that the proposed encryption scheme is more secure,robust,and computationally efficient than some of the recently published similar works.Being computational efficient,our proposed scheme is feasible on many emergent resource-constrained platforms.

摘要： Dear Editors,CRISPR/Cas9-mediated genome editing techniques have triggered a revolution in biology research(Jinek et al.,2012).Cas9 coupled with guide RNAs cuts DNA at precise positions,and the resulting double stranded breaks(DSB)were effectively repaired by non-homologous end joining(NHEJ)pathway in higher eukaryotic cells,including animals and plants.

摘要： Oxygen evolution reaction(OER)is a bottleneck process for many electrochemical devices due to the sluggish kinetics,for which advanced electrocatalysts should be carefully designed.Nickle-based materials have been extensively studied to catalyze OER.However,their performances are still below the expectation and the active sites are often controversial.Herein,we have successfully modulated the electronic and surface properties of layeredβ-Ni(OH)2 by the interlayer ligand engineering,aiming to design novel efficient electrocatalysts and unveil the catalysis mechanism.By one-step solvothermal reaction,alkoxyl substitutedβ-Ni(OH)2 with variable interlayer distances is obtained,and the ethoxyl substituted one(NiEt)shows great potential for efficient OER.With the assistance of powder X-ray diffraction and crystalline structure computational simulation,the formula of alkoxyl substitutedβ-Ni(OH)2 are determined.Operando X-ray absorption spectroscopy studies combined with ex-situ analyses revealed that the critical active species of NiEt is formed via hydroxylation and subsequent de-protonation,with high valent Niδ+(3<δ≤3.66).The corresponding catalytic reaction pathway and mechanism are proposed.

摘要： Recently, many seminal papers deal with the syntheses, stability and superconducting properties of super-hydrides like LaH10 or YH10 under high pressure, reporting critical temperatures near room temperature. In the first run one will assume that the involved metal atoms contribute a number of 3 electrons to the pairing pool corresponding to their valence. However, another possibility may be that the cationic valence is somewhat smaller, for instance only 2.29, resulting in a nominal electron number per cation of σ0 = 0.229 ≈ 3/13 instead of 0.3. Then, we will have a numerical equality to the optimum hole number in the cuprate high-Tc superconductors, a number that reflects the fractal nature of electronic response in superconductors. However, if one still keeps up the oxidation state of +3 of lanthanum, one will need 13 hydrogen atoms to match the optimum σ0. Such composition may be found at the phase boundary between the observed LaH10 and LaH16 phases. Partial ionic replacement is suggested to shift the super-hydride composition into the σ0 optimum. Micro-structural phenomena such as multiple twinning and ferroelastic behavior as observed with cuprates may also influence the superconductivity of super-hydrides. Finally, epitaxial growth of super-hydrides onto a specially cut diamond substrate is proposed.

摘要： Single molecular real-time(SMRT)sequencing,also called third-generation sequencing,is a novel sequencing technique capable of generating extremely long contiguous sequence reads.While conventional short-read sequencing cannot evaluate the linkage of nucleotide substitutions distant from one another,SMRT sequencing can directly demonstrate linkage of nucleotide changes over a span of more than 20 kbp,and thus can be applied to directly examine the haplotypes of viruses or bacteria whose genome structures are changing in real time.In addition,an error correction method(circular consensus sequencing)has been established and repeated sequencing of a single-molecule DNA template can result in extremely high accuracy.The advantages of long read sequencing enable accurate determination of the haplotypes of individual viral clones.SMRT sequencing has been applied in various studies of viral genomes including determination of the full-length contiguous genome sequence of hepatitis C virus(HCV),targeted deep sequencing of the HCV NS5A gene,and assessment of heterogeneity among viral populations.Recently,the emergence of multi-drug resistant HCV viruses has become a significant clinical issue and has been also demonstrated using SMRT sequencing.In this review,we introduce the novel third-generation PacBio RSII/Sequel systems,compare them with conventional next-generation sequencers,and summarize previous studies in which SMRT sequencing technology has been applied for HCV genome analysis.We also refer to another long-read sequencing platform,nanopore sequencing technology,and discuss the advantages,limitations and future perspectives in using these thirdgeneration sequencers for HCV genome analysis.

摘要： The effects of partial substitution of La by Ce and Ni by Al, Fe, or Co in LaNi_5-based alloys on hydrogen storage performance were systematically studied. All samples were prepared using vacuum arc melting in an argon atmosphere. The results showed that for LaNi_(5-x)M_x(M = Al, Fe, or Co) alloys, the lattice constants and unit cell volumes increased with an increasing amount of Al and Fe. On the other hand, these parameters decreased upon partial substitution of La by Ce. In addition, the lattice constant remained almost constant in the La_(0.6)Ce_(0.4)Ni_(5–x)Cox alloys regardless of the value of x(x = 0.3, 0.6, or 0.9), as Ce might enhance the homogeneity of the CaCu_5-type phase in Co-containing alloys. The hydrogen storage properties of the alloys were investigated using pressure, composition, and temperature isotherms. The experimental results showed that the plateau pressure decreased with an increasing content of Al, Fe, or Co, but it increased with Ce addition. Furthermore, the plateau pressures of all Co-containing alloys were almost identical upon substitution with Ce. Finally, the enthalpy(ΔH) and entropy(ΔS) values for all alloys were calculated using van't Hoff plots. The relationship between the lattice parameters and enthalpy changes for hydrogenation will be discussed.

摘要： 1) In order to achieve the visibility of the chitosan macromolecule for the UV optical system of the analytical ultracentrifuge on investigation of the molecular characteristics and polymers interactions, the labeling of chitosan by a new fluorophore of fluorescein-5-isothiocyanat was carried out. 2) Samples of fluorescent chitosan with two different degrees of fluorophore substitution and various degrees of acetylation were obtained. 3) The labeled chitosans with the fluorescein-5-isothiocyanat allowed estimating the sedimentation coefficient and the molecular characteristic in the analytical ultracentrifuge. 4) The sensitivity of the UV-optical system of the analytical ultracentrifuge for the obtained fluorescent samples of chitosan relatively to the fixation of the meniscus and the influence of the wavelength and rotation speed were estimated.

摘要： Cu2ZnSnS4(CZTS)是一种非常有前景的p型半导体材料。然而,其光电转换效率受到大量CuZn和ZnCu反位缺陷导致的开路电压损失的限制。研究者们尝试了很多方法以减少这种损失并提高转换效率,其中,以Ag离子替代CZTS中的Cu 位是研究较为深入且有效的一种方案。本文综述了近年来(Cu1-xAgx)2ZnSnS4(CAZTS)与Ag2ZnSnS4(AZTS)的制备的研究进展。